diff --git a/.github/workflows/e2e-ios.yml b/.github/workflows/e2e-ios.yml
new file mode 100644
index 0000000..cf588d5
--- /dev/null
+++ b/.github/workflows/e2e-ios.yml
@@ -0,0 +1,270 @@
+# Phase-0 iOS E2E harness (Maestro launch smoke).
+#
+# Proves end-to-end: EAS dev-client build → macOS runner → booted sim → hermetic
+# backend on localhost (api-server + chat-ws + fresh Neon branch + seed) → auth →
+# chat-list mounts. See apps/mobile/.maestro/launch-smoke.yaml for what it asserts
+# and why it stops at the empty list (E2EE chats can't be seeded — Phase 1 adds an
+# on-device chat-establishment flow before chat-smoke can run).
+#
+# ── Why hermetic, not staging ────────────────────────────────────────────────
+# The app resolves its backend from BUILD-TIME EXPO_PUBLIC_API_URL /
+# EXPO_PUBLIC_CHAT_WS_URL, falling back to http://localhost:3001 / ws://localhost:8787
+# (apps/mobile/lib/api/url.ts). We build the dev artifact with NO env baked, so at
+# runtime the app hits localhost — which on the sim maps to the runner host, where
+# we boot the backend. Deterministic, disposable, no shared-env pollution.
+#
+# ── Required repo secrets (this stays red until all are set) ──────────────────
+#   EXPO_TOKEN        — EAS build auth. Also run `eas init` once so app.json gets
+#                       extra.eas.projectId (not present yet — prerequisite).
+#   NEON_API_KEY      — provision/destroy the per-run Neon branch.
+#   NEON_PROJECT_ID   — the Neon project to branch from.
+# The chat-ws↔api HMAC is generated per-run below and shared between both
+# processes, so it needs no secret.
+#
+# ── UNVERIFIED from authoring env — confirm on first real run ────────────────
+#   1. SST `Resource.ChatWsHmacSecret.value` under bare `wrangler dev` / `tsx`:
+#      the sst SDK reads process.env.SST_RESOURCE_<Name> (JSON). We inject that
+#      for both processes below. If the SDK also demands SST_RESOURCE_App, add it.
+#   2. Neon pooled vs direct URL: migrate/seed use the DIRECT url (Prisma binary
+#      engine, TCP); api/chat-ws use the POOLED url (Neon HTTP driver). Verify the
+#      neonctl connection-string flags below return the shapes your driver expects.
+#   3. Neon default database-name/role-name — set explicitly if your project's
+#      defaults differ from what neonctl infers.
+#   4. api-server extra env (BETTER_AUTH_SECRET etc.): the .env is not in CI, so
+#      we pass a minimal dev env inline. Add any var services/api/src/lib/auth.ts
+#      requires at boot that isn't here.
+
+name: E2E iOS (Maestro)
+
+on:
+  workflow_dispatch:
+  # Cost-gated: macOS minutes + EAS build. Only on PRs that touch the app or the
+  # backend surface the smoke exercises. Widen once it's proven stable.
+  pull_request:
+    paths:
+      - "apps/mobile/**"
+      - "services/api/**"
+      - "services/chat-ws/**"
+      - "packages/database/**"
+      - ".github/workflows/e2e-ios.yml"
+
+concurrency:
+  group: e2e-ios-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  TURBO_TELEMETRY_DISABLED: 1
+  APP_ID: io.sessions.app # app.json ios.bundleIdentifier
+  API_PORT: "3001"
+  WS_PORT: "8787"
+
+jobs:
+  e2e-ios:
+    name: Launch smoke
+    runs-on: macos-15
+    timeout-minutes: 60
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v6
+
+      - name: Setup Node
+        uses: actions/setup-node@v5
+        with:
+          node-version: 22
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      # api-server imports @repo/chat-mls-core (mlsRouter), whose native binding
+      # is loaded at module init — the server will not boot without index.node.
+      - name: Setup Rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+
+      - name: Cache Rust build
+        uses: Swatinem/rust-cache@v2
+        with:
+          workspaces: packages/chat-mls-core/node
+          cache-on-failure: true
+
+      - name: Build MLS native core
+        run: pnpm --filter @repo/chat-mls-core build:node
+
+      # ── Shared per-run HMAC (chat-ws → api /internal/chat/verify-session) ─────
+      # Both processes read Resource.ChatWsHmacSecret.value via the sst SDK, which
+      # resolves from SST_RESOURCE_ChatWsHmacSecret (JSON). Same value → the
+      # verify-session callback authenticates.
+      - name: Generate dev HMAC secret
+        run: |
+          HMAC="$(openssl rand -hex 32)"
+          echo "::add-mask::$HMAC"
+          echo "SST_RESOURCE_ChatWsHmacSecret={\"value\":\"$HMAC\"}" >> "$GITHUB_ENV"
+
+      # ── Neon: fresh branch per run ────────────────────────────────────────────
+      - name: Provision Neon branch
+        id: neon
+        env:
+          NEON_API_KEY: ${{ secrets.NEON_API_KEY }}
+          NEON_PROJECT_ID: ${{ secrets.NEON_PROJECT_ID }}
+        run: |
+          set -euo pipefail
+          BRANCH="ci-e2e-${GITHUB_RUN_ID}-${GITHUB_RUN_ATTEMPT}"
+          echo "branch=$BRANCH" >> "$GITHUB_OUTPUT"
+          npx neonctl branches create \
+            --project-id "$NEON_PROJECT_ID" \
+            --name "$BRANCH" --output json > /dev/null
+          # Direct (TCP) for Prisma migrate/seed; pooled (HTTP driver) for runtime.
+          DIRECT="$(npx neonctl connection-string "$BRANCH" --project-id "$NEON_PROJECT_ID")"
+          POOLED="$(npx neonctl connection-string "$BRANCH" --project-id "$NEON_PROJECT_ID" --pooled)"
+          echo "::add-mask::$DIRECT"
+          echo "::add-mask::$POOLED"
+          echo "DIRECT_DATABASE_URL=$DIRECT" >> "$GITHUB_ENV"
+          echo "POOLED_DATABASE_URL=$POOLED" >> "$GITHUB_ENV"
+
+      - name: Migrate + seed database
+        # Schema declares both url=env(DATABASE_URL) and directUrl=env(DIRECT_URL).
+        # Migrate + seed run over the DIRECT (unpooled) url on both — migrations
+        # require it, and seeding over the pooler risks prepared-statement quirks.
+        # Runtime api/chat-ws use the POOLED url (Neon HTTP driver) below.
+        env:
+          DATABASE_URL: ${{ env.DIRECT_DATABASE_URL }}
+          DIRECT_URL: ${{ env.DIRECT_DATABASE_URL }}
+        run: |
+          pnpm --filter @repo/database db:migrate:deploy
+          pnpm --filter @repo/database db:seed
+
+      # ── Backend on localhost (same host the sim resolves to) ──────────────────
+      - name: Start api-server
+        env:
+          PORT: ${{ env.API_PORT }}
+          NODE_ENV: development
+          DATABASE_URL: ${{ env.POOLED_DATABASE_URL }}
+          BETTER_AUTH_URL: http://localhost:3001
+          BETTER_AUTH_SECRET: ci-dev-better-auth-secret-not-a-real-secret
+          TRUSTED_ORIGINS: http://localhost:3001
+          # SST_RESOURCE_ChatWsHmacSecret is already in $GITHUB_ENV (masked).
+        run: |
+          # Bypass the package "dev" script (--env-file=.env, which doesn't exist
+          # in CI) and run the entrypoint directly with the env above.
+          nohup pnpm --filter @repo/api-server exec tsx src/server.ts > api.log 2>&1 &
+          echo "api started (pid $!)"
+
+      - name: Start chat-ws (wrangler dev)
+        env:
+          POOLED_DATABASE_URL: ${{ env.POOLED_DATABASE_URL }}
+        run: |
+          # wrangler dev reads secrets from .dev.vars (gitignored; CI-only here).
+          # DATABASE_URL → Neon HTTP driver; SST_RESOURCE_* → sst SDK Resource proxy.
+          cat > services/chat-ws/.dev.vars <<EOF
+          DATABASE_URL=${POOLED_DATABASE_URL}
+          SST_RESOURCE_ChatWsHmacSecret=${SST_RESOURCE_ChatWsHmacSecret}
+          EOF
+          ( cd services/chat-ws && nohup pnpm exec wrangler dev --local \
+              --port "${WS_PORT}" --persist-to .wrangler/state > ../../ws.log 2>&1 & )
+          echo "chat-ws starting"
+
+      - name: Wait for backend
+        run: |
+          set -e
+          for name_port in "api:${API_PORT}" "ws:${WS_PORT}"; do
+            name="${name_port%%:*}"; port="${name_port##*:}"
+            echo "waiting for $name on :$port"
+            for i in $(seq 1 60); do
+              if nc -z localhost "$port"; then echo "$name up"; break; fi
+              if [ "$i" = "60" ]; then
+                echo "::error::$name never came up on :$port"; cat api.log ws.log || true; exit 1
+              fi
+              sleep 2
+            done
+          done
+
+      # ── EAS simulator build (cloud) → download .app ──────────────────────────
+      - name: Setup EAS
+        uses: expo/expo-github-action@v8
+        with:
+          eas-version: 20.5.1
+          token: ${{ secrets.EXPO_TOKEN }}
+
+      - name: Build iOS simulator app (EAS)
+        id: build
+        working-directory: apps/mobile
+        run: |
+          set -euo pipefail
+          # preview-simulator = RELEASE build with the JS bundle EMBEDDED — no
+          # dev-client launcher, no Metro needed (a dev-client build boots to
+          # "No development servers found" in CI). No EXPO_PUBLIC_* baked → the
+          # `??` fallback in lib/api/url.ts hands back localhost at runtime.
+          META="$(eas build --profile preview-simulator --platform ios \
+                    --non-interactive --wait --json)"
+          URL="$(echo "$META" | jq -r '.[0].artifacts.applicationArchiveUrl')"
+          echo "artifact=$URL" >> "$GITHUB_OUTPUT"
+
+      - name: Download + extract app
+        run: |
+          set -euo pipefail
+          curl -L -o build.tar.gz "${{ steps.build.outputs.artifact }}"
+          mkdir -p build && tar -xzf build.tar.gz -C build
+          APP_PATH="$(find build -maxdepth 2 -name '*.app' -type d | head -n1)"
+          echo "APP_PATH=$APP_PATH" >> "$GITHUB_ENV"
+
+      # ── Boot sim, install, run Maestro ────────────────────────────────────────
+      - name: Boot simulator + install app
+        run: |
+          set -euo pipefail
+          UDID="$(xcrun simctl list devices available | grep -m1 'iPhone 16' \
+                    | grep -oE '[0-9A-F-]{36}')"
+          echo "SIM_UDID=$UDID" >> "$GITHUB_ENV"
+          xcrun simctl boot "$UDID" || true
+          xcrun simctl bootstatus "$UDID" -b
+          xcrun simctl install "$UDID" "$APP_PATH"
+
+      - name: Cache Maestro
+        uses: actions/cache@v4
+        with:
+          path: ~/.maestro
+          key: maestro-${{ runner.os }}-1.39.0 # pin your version
+      - name: Install Maestro
+        run: |
+          if [ ! -x "$HOME/.maestro/bin/maestro" ]; then
+            export MAESTRO_VERSION=1.39.0
+            curl -Ls "https://get.maestro.mobile.dev" | bash
+          fi
+          echo "$HOME/.maestro/bin" >> "$GITHUB_PATH"
+      - name: Run launch smoke
+        env:
+          MAESTRO_APP_ID: ${{ env.APP_ID }}
+        run: |
+          # Pass MAESTRO_APP_ID via --env, not the process environment: pinned
+          # Maestro (1.39.0) does not interpolate `appId: ${MAESTRO_APP_ID}`
+          # from the OS env, so it resolved to null ("Unable to launch app null").
+          maestro --device "$SIM_UDID" test \
+            --env MAESTRO_APP_ID="$MAESTRO_APP_ID" \
+            apps/mobile/.maestro/launch-smoke.yaml \
+            --format junit --output maestro-report.xml
+
+      - name: Upload Maestro artifacts
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: maestro-e2e
+          path: |
+            maestro-report.xml
+            ~/.maestro/tests/**
+            api.log
+            ws.log
+          if-no-files-found: ignore
+
+      # ── Teardown ──────────────────────────────────────────────────────────────
+      - name: Destroy Neon branch
+        if: always()
+        env:
+          NEON_API_KEY: ${{ secrets.NEON_API_KEY }}
+          NEON_PROJECT_ID: ${{ secrets.NEON_PROJECT_ID }}
+        run: |
+          npx neonctl branches delete "${{ steps.neon.outputs.branch }}" \
+            --project-id "$NEON_PROJECT_ID" || true
diff --git a/.github/workflows/native-artifacts.yml b/.github/workflows/native-artifacts.yml
new file mode 100644
index 0000000..83eb61b
--- /dev/null
+++ b/.github/workflows/native-artifacts.yml
@@ -0,0 +1,138 @@
+# Producer for gitignored native binaries (Rust → xcframework), consumed by
+# scripts/fetch-native-artifacts.sh (EAS eas-build-pre-install hook + CI).
+#
+# Model — the compiled xcframework is non-reproducible (embedded timestamps +
+# build paths, see .gitignore), so CI is the SOLE builder/publisher: it builds,
+# uploads the asset to R2 keyed by the Rust SOURCE fingerprint, and commits the
+# refreshed checksum manifest + .artifact-key. That published asset therefore
+# always matches the committed manifest the consumer verifies against.
+#
+# Idempotent: if the asset for the current source key already exists on R2, the
+# expensive Rust/iOS build is skipped — reruns and non-Rust PR syncs are cheap.
+#
+# ── Required config ───────────────────────────────────────────────────────────
+#   secrets.R2_ACCOUNT_ID          Cloudflare account id (R2 S3 endpoint host)
+#   secrets.R2_ACCESS_KEY_ID       R2 access key (Object Read & Write)
+#   secrets.R2_SECRET_ACCESS_KEY   R2 secret key
+#   vars.R2_BUCKET                 bucket name, e.g. mortstack-native
+#   vars.R2_PUBLIC_BASE_URL        public-read base, e.g. https://native.<zone>/mortstack
+name: Native artifacts
+
+on:
+  workflow_dispatch:
+  push:
+    branches: [main]
+    paths:
+      - "packages/chat-mls-core/Cargo.toml"
+      - "packages/chat-mls-core/Cargo.lock"
+      - "packages/chat-mls-core/src/**"
+      - "packages/chat-mls-core/scripts/build-mls.sh"
+      - ".github/workflows/native-artifacts.yml"
+  pull_request:
+    paths:
+      - "packages/chat-mls-core/Cargo.toml"
+      - "packages/chat-mls-core/Cargo.lock"
+      - "packages/chat-mls-core/src/**"
+      - "packages/chat-mls-core/scripts/build-mls.sh"
+      - ".github/workflows/native-artifacts.yml"
+
+concurrency:
+  group: native-artifacts-${{ github.ref }}
+  cancel-in-progress: false
+
+permissions:
+  contents: write # commit refreshed manifest + .artifact-key back
+
+jobs:
+  ios:
+    name: chat_mls_coreFFI (iOS)
+    runs-on: macos-15
+    timeout-minutes: 60
+    env:
+      PKG: packages/chat-mls-core
+      R2_PUBLIC_BASE_URL: ${{ vars.R2_PUBLIC_BASE_URL }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+        with:
+          # Push commits back to the PR/main branch, not a detached HEAD.
+          ref: ${{ github.head_ref || github.ref_name }}
+
+      - name: Compute artifact key
+        id: key
+        run: |
+          KEY="$(bash scripts/artifact-key.sh "$PKG" ios)"
+          echo "key=$KEY" >> "$GITHUB_OUTPUT"
+          echo "asset=chat_mls_coreFFI-ios-$KEY.tar.gz" >> "$GITHUB_OUTPUT"
+
+      - name: Already published?
+        id: exists
+        run: |
+          URL="${R2_PUBLIC_BASE_URL%/}/${{ steps.key.outputs.asset }}"
+          if curl -fsI "$URL" >/dev/null 2>&1; then
+            echo "found=true" >> "$GITHUB_OUTPUT"
+            echo "✓ $URL already published — skipping build"
+          else
+            echo "found=false" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Select full Xcode
+        if: steps.exists.outputs.found != 'true'
+        run: sudo xcode-select -s /Applications/Xcode.app/Contents/Developer
+
+      - name: Setup Rust + iOS targets
+        if: steps.exists.outputs.found != 'true'
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          targets: aarch64-apple-ios,aarch64-apple-ios-sim,x86_64-apple-ios
+
+      - name: Cache Rust build
+        if: steps.exists.outputs.found != 'true'
+        uses: Swatinem/rust-cache@v2
+        with:
+          workspaces: packages/chat-mls-core
+
+      - name: Build iOS xcframework
+        if: steps.exists.outputs.found != 'true'
+        run: bash "$PKG/scripts/build-mls.sh" ios
+
+      - name: Package
+        if: steps.exists.outputs.found != 'true'
+        run: |
+          tar czf "${{ steps.key.outputs.asset }}" \
+            -C "$PKG/ios" chat_mls_coreFFI.xcframework
+
+      - name: Upload to R2
+        if: steps.exists.outputs.found != 'true'
+        env:
+          AWS_ACCESS_KEY_ID: ${{ secrets.R2_ACCESS_KEY_ID }}
+          AWS_SECRET_ACCESS_KEY: ${{ secrets.R2_SECRET_ACCESS_KEY }}
+          AWS_DEFAULT_REGION: auto
+          R2_ACCOUNT_ID: ${{ secrets.R2_ACCOUNT_ID }}
+          R2_BUCKET: ${{ vars.R2_BUCKET }}
+        run: |
+          aws s3 cp "${{ steps.key.outputs.asset }}" \
+            "s3://${R2_BUCKET}/${{ steps.key.outputs.asset }}" \
+            --endpoint-url "https://${R2_ACCOUNT_ID}.r2.cloudflarestorage.com" \
+            --only-show-errors
+          echo "→ uploaded ${{ steps.key.outputs.asset }}"
+
+      # The build refreshes ios/*.sha256 + ios/Sources/ and we stamp the key.
+      # Committing them (only when changed) keeps the consumer's verify gate in
+      # lockstep with the asset just published.
+      - name: Commit refreshed manifest + key
+        if: steps.exists.outputs.found != 'true' && github.event_name != 'pull_request' || (steps.exists.outputs.found != 'true' && github.event.pull_request.head.repo.full_name == github.repository)
+        run: |
+          echo "${{ steps.key.outputs.key }}" > "$PKG/ios/.artifact-key"
+          git config user.name  "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          git add "$PKG/ios/chat_mls_coreFFI.xcframework.sha256" \
+                  "$PKG/ios/Sources.sha256" \
+                  "$PKG/ios/Sources" \
+                  "$PKG/ios/.artifact-key"
+          if git diff --cached --quiet; then
+            echo "nothing to commit"
+          else
+            git commit -m "chore(native): publish chat_mls_coreFFI ios (${{ steps.key.outputs.key }})"
+            git push
+          fi
diff --git a/apps/mobile/.maestro/launch-smoke.yaml b/apps/mobile/.maestro/launch-smoke.yaml
new file mode 100644
index 0000000..80bc91a
--- /dev/null
+++ b/apps/mobile/.maestro/launch-smoke.yaml
@@ -0,0 +1,50 @@
+# Phase-0 launch smoke — proves the whole E2E harness end to end WITHOUT a chat.
+#
+# What it asserts: the built dev-client boots, the auth gate renders, a seeded
+# credential sign-in reaches the backend (Better Auth over the API), and the
+# app lands on the conversation list. It deliberately stops at the EMPTY list —
+# a fresh CI backend has zero chats (the Prisma seed creates accounts/profiles
+# only; E2EE chats are provisioned on-device at create-time and can't be
+# seeded). Asserting a chat/send/react is Phase 1, which needs an on-device
+# chat-establishment flow first (see .maestro/README.md).
+#
+# So a green run here means: EAS build OK → sim boot OK → api-server + chat-ws
+# reachable on localhost → auth OK → chat-list route mounts. That covers the
+# large majority of "did we break the app/backend contract" breakage.
+#
+# Preconditions: app installed on a booted sim; api-server (:3001) + chat-ws
+# (:8787) up on the runner; DB seeded with alice (packages/database/prisma/
+# seed.ts, SEED_PASSWORD). Set MAESTRO_APP_ID (e.g. io.sessions.app).
+appId: ${MAESTRO_APP_ID}
+---
+- launchApp
+
+# Cold-start sign-in. Mirrors chat-smoke.yaml: launchApp relaunches the process
+# and the Better Auth session does not rehydrate, so we land on the auth gate.
+# Gated on "Login" being visible — a no-op if a session ever does persist.
+# Creds come from the DB seed (SEED_PASSWORD = "password123").
+- runFlow:
+    when:
+      visible: "Login"
+    commands:
+      - tapOn: "Email Address"
+      - inputText: "alice@example.com"
+      - tapOn: "Password"
+      - inputText: "password123"
+      # Password field has enterKeyHint="go" + onSubmitEditing → submit via the
+      # keyboard return key (same rationale as chat-smoke: avoids hideKeyboard
+      # and a Login-button tap the keyboard can overlap).
+      - pressKey: Enter
+
+# Landed on the conversation list. Anchor on the empty-state headline the
+# chat-list renders when alice has no chats ("No chats yet", apps/mobile/app/
+# (tabs)/index.tsx). This is the Phase-0 success signal: auth cleared and the
+# authed route mounted against a live backend.
+- extendedWaitUntil:
+    visible: "No chats yet"
+    timeout: 20000
+
+# Belt-and-braces: the sticky New Chat action bar is always present on the list
+# screen. Asserting it too guards against a future empty-state copy change
+# silently passing on a half-rendered screen.
+- assertVisible: "New Chat"
diff --git a/apps/mobile/app.json b/apps/mobile/app.json
index 9a300ca..1ec53a1 100644
--- a/apps/mobile/app.json
+++ b/apps/mobile/app.json
@@ -20,7 +20,8 @@
         "com.apple.security.application-groups": ["group.io.sessions.shared"]
       },
       "infoPlist": {
-        "UIBackgroundModes": ["remote-notification"]
+        "UIBackgroundModes": ["remote-notification"],
+        "ITSAppUsesNonExemptEncryption": false
       }
     },
     "android": {
@@ -56,9 +57,16 @@
     },
     "extra": {
       "_complianceTodos": [
+        "Before first App Store / Play public submission:",
+        "1. iOS: set ios.config.usesNonExemptEncryption = true. SQLCipher + libsodium → ECCN 5D002 (mass-market via License Exception ENC). US entity → file annual BIS self-classification (CSV to crypt-supp8@bis.doc.gov by Feb 1). Non-US entity → check national regime (UK ECJU / EU dual-use), usually no filing.",
         "Before first App Store / Play public submission:",
         "1. iOS: set ios.config.usesNonExemptEncryption = true. SQLCipher + libsodium → ECCN 5D002 (mass-market via License Exception ENC). US entity → file annual BIS self-classification (CSV to crypt-supp8@bis.doc.gov by Feb 1). Non-US entity → check national regime (UK ECJU / EU dual-use), usually no filing."
-      ]
-    }
+      ],
+      "router": {},
+      "eas": {
+        "projectId": "88084928-70f3-4f8c-987f-e5bbee6779cf"
+      }
+    },
+    "owner": "lxm7"
   }
 }
diff --git a/apps/mobile/app/(tabs)/index.tsx b/apps/mobile/app/(tabs)/index.tsx
index 612fae7..35d4112 100644
--- a/apps/mobile/app/(tabs)/index.tsx
+++ b/apps/mobile/app/(tabs)/index.tsx
@@ -127,7 +127,7 @@ export default function ChatListScreen() {
       >
         <XStack
           height={64}
-          px={20}
+          px="$screen"
           alignItems="center"
           justifyContent="space-between"
         >
@@ -158,7 +158,7 @@ export default function ChatListScreen() {
 
       {/* Section title */}
       <XStack
-        px={20}
+        px="$screen"
         pt="$md"
         pb="$xs"
         alignItems="center"
@@ -233,7 +233,7 @@ export default function ChatListScreen() {
         borderTopColor="$outlineVariant"
         paddingTop={12}
         paddingBottom={insets.bottom + 12}
-        px={20}
+        px="$screen"
       >
         <Button
           variant="primary"
diff --git a/apps/mobile/app/chat-crypto-debug.tsx b/apps/mobile/app/chat-crypto-debug.tsx
index e1797ef..d77dca9 100644
--- a/apps/mobile/app/chat-crypto-debug.tsx
+++ b/apps/mobile/app/chat-crypto-debug.tsx
@@ -194,7 +194,7 @@ export default function ChatCryptoDebug() {
           device identity
         </Text>
         {identityError ? (
-          <Text color="red" fontSize="$2">
+          <Text color="$error" fontSize="$2">
             {identityError}
           </Text>
         ) : identity ? (
diff --git a/apps/mobile/app/chat/[chatId]/inspect/[serverMsgId].tsx b/apps/mobile/app/chat/[chatId]/inspect/[serverMsgId].tsx
index b9486f6..54e5fe0 100644
--- a/apps/mobile/app/chat/[chatId]/inspect/[serverMsgId].tsx
+++ b/apps/mobile/app/chat/[chatId]/inspect/[serverMsgId].tsx
@@ -192,8 +192,8 @@ export default function InspectScreen() {
       >
         <XStack alignItems="center" gap="$xs">
           <YStack
-            width={40}
-            height={40}
+            width={44}
+            height={44}
             alignItems="center"
             justifyContent="center"
             borderRadius="$full"
@@ -205,8 +205,8 @@ export default function InspectScreen() {
           </YStack>
           <HeadlineMd flex={1}>Inspect encryption</HeadlineMd>
           <YStack
-            width={40}
-            height={40}
+            width={44}
+            height={44}
             alignItems="center"
             justifyContent="center"
             borderRadius="$full"
diff --git a/apps/mobile/app/settings/blocks.tsx b/apps/mobile/app/settings/blocks.tsx
index 3cc6005..cedc1ec 100644
--- a/apps/mobile/app/settings/blocks.tsx
+++ b/apps/mobile/app/settings/blocks.tsx
@@ -94,7 +94,7 @@ export default function BlocksScreen() {
             No blocked accounts
           </Text>
           {error && (
-            <Text fontSize="$2" color="#dc2626">
+            <Text fontSize="$2" color="$error">
               {error}
             </Text>
           )}
diff --git a/apps/mobile/app/settings/delete-account.tsx b/apps/mobile/app/settings/delete-account.tsx
index ee553bd..6d92740 100644
--- a/apps/mobile/app/settings/delete-account.tsx
+++ b/apps/mobile/app/settings/delete-account.tsx
@@ -16,8 +16,6 @@ import { authClient } from "@/lib/auth/client";
 import { useAuthStore } from "@/store/auth";
 import { clearSessionToken } from "@/lib/auth/session";
 
-const DESTRUCTIVE = "#dc2626";
-
 export default function DeleteAccountScreen() {
   const router = useRouter();
   const clearSession = useAuthStore((s) => s.clearSession);
@@ -83,7 +81,7 @@ export default function DeleteAccountScreen() {
       </XStack>
 
       <YStack px="$4" py="$3" gap="$4">
-        <Text fontSize="$5" fontWeight="700" color={DESTRUCTIVE}>
+        <Text fontSize="$5" fontWeight="700" color="$error">
           This cannot be undone.
         </Text>
 
@@ -124,7 +122,7 @@ export default function DeleteAccountScreen() {
         </YStack>
 
         {error && (
-          <Text fontSize="$2" color={DESTRUCTIVE}>
+          <Text fontSize="$2" color="$error">
             {error}
           </Text>
         )}
@@ -134,12 +132,12 @@ export default function DeleteAccountScreen() {
           disabled={!canSubmit}
           opacity={canSubmit ? 1 : 0.5}
           onPress={onDelete}
-          style={{ backgroundColor: DESTRUCTIVE }}
+          backgroundColor="$error"
         >
           {busy ? (
             <Spinner size="small" />
           ) : (
-            <Text color="white" fontWeight="700">
+            <Text color="$onError" fontWeight="700">
               Delete my account
             </Text>
           )}
diff --git a/apps/mobile/app/settings/index.tsx b/apps/mobile/app/settings/index.tsx
index e0ed87f..93130d1 100644
--- a/apps/mobile/app/settings/index.tsx
+++ b/apps/mobile/app/settings/index.tsx
@@ -9,8 +9,6 @@ import { Button, Switch, Text, View, XStack, YStack } from "tamagui";
 
 import { useSettingsStore } from "@/store/settings";
 
-const DESTRUCTIVE = "#dc2626";
-
 export default function SettingsScreen() {
   const router = useRouter();
   const readReceipts = useSettingsStore((s) => s.readReceipts);
@@ -56,7 +54,7 @@ export default function SettingsScreen() {
         </Text>
         <SettingsRow
           label="Delete account"
-          color={DESTRUCTIVE}
+          color="$error"
           onPress={() => router.push("/settings/delete-account" as never)}
         />
       </YStack>
diff --git a/apps/mobile/eas.json b/apps/mobile/eas.json
new file mode 100644
index 0000000..4792160
--- /dev/null
+++ b/apps/mobile/eas.json
@@ -0,0 +1,37 @@
+{
+  "cli": {
+    "version": ">= 18.7.0",
+    "appVersionSource": "remote"
+  },
+  "build": {
+    "development": {
+      "developmentClient": true,
+      "distribution": "internal",
+      "env": {
+        "R2_PUBLIC_BASE_URL": "https://pub-2ffb489eefe84de8b9b32e409fd30957.r2.dev"
+      }
+    },
+    "development-simulator": {
+      "extends": "development",
+      "ios": {
+        "simulator": true
+      }
+    },
+    "preview": {
+      "distribution": "internal",
+      "env": {
+        "R2_PUBLIC_BASE_URL": "https://pub-2ffb489eefe84de8b9b32e409fd30957.r2.dev"
+      }
+    },
+    "preview-simulator": {
+      "extends": "preview",
+      "ios": { "simulator": true }
+    },
+    "production": {
+      "autoIncrement": true
+    }
+  },
+  "submit": {
+    "production": {}
+  }
+}
diff --git a/apps/mobile/lib/chat/components/TypingIndicator.tsx b/apps/mobile/lib/chat/components/TypingIndicator.tsx
index 9cc91d1..a76914c 100644
--- a/apps/mobile/lib/chat/components/TypingIndicator.tsx
+++ b/apps/mobile/lib/chat/components/TypingIndicator.tsx
@@ -58,7 +58,7 @@ function Dot({
 export function TypingIndicator() {
   const theme = useTheme();
   const reduced = useReducedMotion();
-  const dotColor = theme.onSurfaceVariant?.val ?? "#888";
+  const dotColor = theme.onSurfaceVariant?.val ?? "#3a494a";
 
   return (
     <YStack
diff --git a/apps/mobile/package.json b/apps/mobile/package.json
index ea59ba0..5cab516 100644
--- a/apps/mobile/package.json
+++ b/apps/mobile/package.json
@@ -7,6 +7,7 @@
     "sqlcipher": true
   },
   "scripts": {
+    "eas-build-pre-install": "bash ../../scripts/fetch-native-artifacts.sh \"${EAS_BUILD_PLATFORM:-ios}\"",
     "dev": "expo start --dev-client",
     "start": "expo start --dev-client -c",
     "ios": "expo start --dev-client -c --ios",
diff --git a/packages/chat-mls-core/ios/.artifact-key b/packages/chat-mls-core/ios/.artifact-key
new file mode 100644
index 0000000..c68ab65
--- /dev/null
+++ b/packages/chat-mls-core/ios/.artifact-key
@@ -0,0 +1 @@
+d61c7f30119f8999
diff --git a/packages/ui/src/glacier/avatar.tsx b/packages/ui/src/glacier/avatar.tsx
index b89b8bc..62d381d 100644
--- a/packages/ui/src/glacier/avatar.tsx
+++ b/packages/ui/src/glacier/avatar.tsx
@@ -3,13 +3,20 @@
 // accent palette; fill is that hue at 15%, initials at full opacity.
 import { Image, Text, YStack, styled } from "tamagui";
 
+import { palette } from "../tamagui.config";
+
 type Size = "sm" | "md" | "lg";
 type Status = "online" | "away" | "offline";
 
 const DIAMETER: Record<Size, number> = { sm: 32, md: 40, lg: 48 };
 
-// Fixed accent palette (THEME §2): primary teal, secondary violet, slate.
-const HUES = ["#00696e", "#5400c3", "#3a494a"] as const;
+// Fixed accent palette (THEME §2): primary teal, secondary violet, slate —
+// sourced from the token palette so a §2 recolour propagates here.
+const HUES = [
+  palette.ice700,
+  palette.violet500,
+  palette.onSurfaceVariant,
+] as const;
 
 function hueFor(seed: string): string {
   let h = 0;
diff --git a/packages/ui/src/glacier/button.tsx b/packages/ui/src/glacier/button.tsx
index 62c1192..b0d2133 100644
--- a/packages/ui/src/glacier/button.tsx
+++ b/packages/ui/src/glacier/button.tsx
@@ -1,11 +1,16 @@
 // Glacier Button (components/Button.md). Three variants share one shape
-// language; sizes sm/md/lg all meet the 44pt tap-target floor. Icon-agnostic:
-// pass rendered icon nodes via `icon` / `iconAfter` (screens own the icon set).
+// language. md/lg are ≥44pt tall; sm is a compact 36pt but reaches the 44pt
+// tap-target floor (THEME §8) via hitSlop, so the touch area is always ≥44.
+// Icon-agnostic: pass rendered icon nodes via `icon` / `iconAfter` (screens
+// own the icon set).
 import type { ReactNode } from "react";
-import { styled, Text, YStack, type GetProps } from "tamagui";
+import { styled, YStack, type GetProps } from "tamagui";
+
+import { Label } from "./typography";
 
 const ButtonFrame = styled(YStack, {
   name: "GlacierButton",
+  accessibilityRole: "button",
   flexDirection: "row",
   alignItems: "center",
   justifyContent: "center",
@@ -47,13 +52,10 @@ const ButtonFrame = styled(YStack, {
   defaultVariants: { variant: "primary", size: "md" },
 });
 
-const ButtonLabel = styled(Text, {
+// Composes the Label preset (THEME §3.1 label: body 13/16/500) — only the
+// per-variant colour differs.
+const ButtonLabel = styled(Label, {
   name: "GlacierButtonLabel",
-  fontFamily: "$body",
-  fontSize: 13,
-  lineHeight: 16,
-  fontWeight: "500",
-  letterSpacing: 0.26,
 
   variants: {
     variant: {
@@ -85,10 +87,21 @@ export function Button({
   icon,
   iconAfter,
   children,
+  disabled,
   ...rest
 }: ButtonProps) {
+  // sm is 36pt tall; extend the touch area by 4pt top/bottom so it meets the
+  // 44pt floor (THEME §8) without changing the visual size.
+  const hitSlop = size === "sm" ? { top: 4, bottom: 4 } : undefined;
   return (
-    <ButtonFrame variant={variant} size={size} {...rest}>
+    <ButtonFrame
+      variant={variant}
+      size={size}
+      disabled={disabled}
+      hitSlop={hitSlop}
+      accessibilityState={{ disabled: !!disabled }}
+      {...rest}
+    >
       {icon}
       {typeof children === "string" ? (
         <ButtonLabel variant={variant}>{children}</ButtonLabel>
diff --git a/packages/ui/src/glacier/chat-bubble.tsx b/packages/ui/src/glacier/chat-bubble.tsx
index 8643ab4..17c8296 100644
--- a/packages/ui/src/glacier/chat-bubble.tsx
+++ b/packages/ui/src/glacier/chat-bubble.tsx
@@ -4,7 +4,7 @@
 // inside. Presentational only — the screen wraps it in a Pressable for
 // long-press (→ the crypto inspector).
 import type { ReactNode } from "react";
-import { Text, XStack, YStack, styled } from "tamagui";
+import { XStack, YStack, styled } from "tamagui";
 import { LinearGradient } from "@tamagui/linear-gradient";
 
 import { BodyMd, BodySm, Meta } from "./typography";
@@ -83,7 +83,7 @@ export function ChatBubble({
           borderWidth={failed ? 1 : 0}
           borderColor={failed ? "$error" : "transparent"}
           // soft ownership glow (THEME §5 — interactive/owned only)
-          shadowColor="#007a74"
+          shadowColor="$ownGlow"
           shadowOpacity={0.2}
           shadowRadius={10}
           shadowOffset={{ width: 0, height: 4 }}
@@ -158,18 +158,7 @@ export function DayDivider({ label }: { label: string }) {
         paddingHorizontal="$sm"
         paddingVertical={6}
       >
-        <Text
-          fontFamily="$body"
-          fontSize={12}
-          lineHeight={16}
-          fontWeight="500"
-          letterSpacing={0.96}
-          textTransform="uppercase"
-          color="$onSurfaceVariant"
-          fontVariant={["tabular-nums"]}
-        >
-          {label}
-        </Text>
+        <Meta>{label}</Meta>
       </YStack>
     </YStack>
   );
diff --git a/packages/ui/src/glacier/composer.tsx b/packages/ui/src/glacier/composer.tsx
index bb19139..06f2319 100644
--- a/packages/ui/src/glacier/composer.tsx
+++ b/packages/ui/src/glacier/composer.tsx
@@ -47,6 +47,7 @@ const ComposerPill = styled(XStack, {
 
 const SendButton = styled(YStack, {
   name: "GlacierSendButton",
+  accessibilityRole: "button",
   width: 44,
   height: 44,
   borderRadius: "$md",
@@ -55,7 +56,7 @@ const SendButton = styled(YStack, {
 
   variants: {
     active: {
-      true: { backgroundColor: "rgba(0,105,110,0.12)" },
+      true: { backgroundColor: "$primaryTint" },
       false: { backgroundColor: "$surfaceContainerLow" },
     },
   } as const,
@@ -118,6 +119,8 @@ export function Composer({
       <SendButton
         testID="composer-send"
         active={active}
+        accessibilityLabel="Send message"
+        accessibilityState={{ disabled: !active }}
         onPress={active ? onSend : undefined}
         pressStyle={active ? { opacity: 0.85 } : undefined}
       >
diff --git a/packages/ui/src/glacier/inspector-pane.tsx b/packages/ui/src/glacier/inspector-pane.tsx
index 8ca075b..f0ce5fc 100644
--- a/packages/ui/src/glacier/inspector-pane.tsx
+++ b/packages/ui/src/glacier/inspector-pane.tsx
@@ -6,6 +6,8 @@
 import type { ReactNode } from "react";
 import { Text, XStack, YStack, styled } from "tamagui";
 
+import { BodyLg, Meta, MonoMd } from "./typography";
+
 const PaneFrame = styled(YStack, {
   name: "GlacierInspectorPane",
   borderRadius: "$lg",
@@ -20,9 +22,9 @@ const PaneFrame = styled(YStack, {
         borderColor: "$outlineVariant",
       },
       emphasized: {
-        backgroundColor: "rgba(0,105,110,0.06)",
+        backgroundColor: "$revealFill",
         borderWidth: 0.5,
-        borderColor: "rgba(0,105,110,0.25)",
+        borderColor: "$revealBorder",
         shadowColor: "$primary",
         shadowOpacity: 0.1,
         shadowRadius: 20,
@@ -32,15 +34,10 @@ const PaneFrame = styled(YStack, {
   defaultVariants: { tone: "recessed" },
 });
 
-const PaneLabel = styled(Text, {
+// Composes the Meta preset (THEME §3.1 meta: 12/16/500, uppercase, tabular) —
+// only the tone colour differs.
+const PaneLabel = styled(Meta, {
   name: "GlacierPaneLabel",
-  fontFamily: "$body",
-  fontSize: 12,
-  lineHeight: 16,
-  fontWeight: "500",
-  letterSpacing: 0.96,
-  textTransform: "uppercase",
-  fontVariant: ["tabular-nums"],
 
   variants: {
     tone: {
@@ -50,22 +47,16 @@ const PaneLabel = styled(Text, {
   } as const,
 });
 
-// Ciphertext / hexdump — dim, recessed, machine.
-export const PaneMonoContent = styled(Text, {
+// Ciphertext / hexdump — dim, recessed, machine. Composes MonoMd (THEME §3.1
+// mono-md: mono 13/20/500, tabular).
+export const PaneMonoContent = styled(MonoMd, {
   name: "GlacierPaneMono",
-  fontFamily: "$mono",
-  fontSize: 13,
-  lineHeight: 20,
-  color: "$onSurfaceVariant",
-  fontVariant: ["tabular-nums"],
 });
 
-// Plaintext — bright, forward, human.
-export const PanePlaintext = styled(Text, {
+// Plaintext — bright, forward, human. Composes BodyLg (18/28) + the forward
+// emphasis (weight 600, on-primary-container ink).
+export const PanePlaintext = styled(BodyLg, {
   name: "GlacierPanePlaintext",
-  fontFamily: "$body",
-  fontSize: 18,
-  lineHeight: 28,
   fontWeight: "600",
   color: "$onPrimaryContainer",
 });
diff --git a/packages/ui/src/glacier/list-row.tsx b/packages/ui/src/glacier/list-row.tsx
index 988851f..e8caf60 100644
--- a/packages/ui/src/glacier/list-row.tsx
+++ b/packages/ui/src/glacier/list-row.tsx
@@ -6,9 +6,11 @@ import { Text, XStack, YStack, styled } from "tamagui";
 
 import { Avatar, type AvatarProps } from "./avatar";
 import { Badge } from "./badge";
+import { Meta } from "./typography";
 
 const RowFrame = styled(XStack, {
   name: "GlacierListRow",
+  accessibilityRole: "button",
   alignItems: "center",
   gap: "$sm",
   paddingHorizontal: "$sm",
@@ -20,7 +22,7 @@ const RowFrame = styled(XStack, {
 const RowTitle = styled(Text, {
   name: "RowTitle",
   fontFamily: "$body",
-  fontSize: 15,
+  fontSize: 16, // body-md (was off-scale 15) — THEME §3.1
   lineHeight: 20,
   color: "$onSurface",
   numberOfLines: 1,
@@ -46,14 +48,10 @@ const RowPreview = styled(Text, {
   } as const,
 });
 
-const RowTimestamp = styled(Text, {
+// Composes the Meta preset (THEME §3.1 meta: 12/16/500, uppercase, tabular) —
+// only the unread emphasis (primary + 600) differs.
+const RowTimestamp = styled(Meta, {
   name: "RowTimestamp",
-  fontFamily: "$body",
-  fontSize: 12,
-  lineHeight: 16,
-  letterSpacing: 0.96,
-  textTransform: "uppercase",
-  fontVariant: ["tabular-nums"],
   variants: {
     unread: {
       true: { color: "$primary", fontWeight: "600" },
diff --git a/packages/ui/src/tamagui.config.ts b/packages/ui/src/tamagui.config.ts
index 980e898..02165ac 100644
--- a/packages/ui/src/tamagui.config.ts
+++ b/packages/ui/src/tamagui.config.ts
@@ -151,7 +151,7 @@ const monoFont = createFont({
 // ── Raw palette ─────────────────────────────────────────────────────────────
 // THEME §2 hexes. Themes map these to semantic slots below; components never
 // reference raw hex — they use the semantic theme tokens ($primary, $surface…).
-const palette = {
+export const palette = {
   // Shared accent ramp (§2.1)
   ice100: "#e6f7ff",
   ice300: "#7dd3fc",
@@ -180,6 +180,13 @@ const palette = {
   errorContainer: "#ffdad6",
   success: "#0f7a5a",
 
+  // Reveal / glow (THEME §2.3, §5) — the primary hue at alpha for tinted panels
+  // and ownership glows. `reveal-glow` in the doc is realised as these slots.
+  revealFill: "rgba(0,105,110,0.06)", // emphasized inspector panel fill
+  revealBorder: "rgba(0,105,110,0.25)", // emphasized inspector panel border
+  primaryTint: "rgba(0,105,110,0.12)", // active/pressed primary affordance fill
+  ownGlow: "#007a74", // outgoing-bubble ownership glow (shadow hue)
+
   black: "#000000",
   white: "#ffffff",
 } as const;
@@ -223,6 +230,7 @@ export const tokens = createTokens({
     lg: 40,
     xl: 64,
     gutter: 16,
+    screen: 20, // THEME §4 margin.mobile — outer screen gutter
   },
   radius: {
     0: 0,
@@ -280,6 +288,12 @@ const light = {
   verified: palette.success,
   tamper: palette.error,
 
+  // Reveal / glow slots (THEME §2.3, §5) — see palette above.
+  revealFill: palette.revealFill,
+  revealBorder: palette.revealBorder,
+  primaryTint: palette.primaryTint,
+  ownGlow: palette.ownGlow,
+
   // Tamagui built-in interaction slots
   backgroundHover: palette.surfaceContainerLow,
   backgroundPress: palette.surfaceContainer,
diff --git a/scripts/artifact-key.sh b/scripts/artifact-key.sh
new file mode 100755
index 0000000..c590c08
--- /dev/null
+++ b/scripts/artifact-key.sh
@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+# Deterministic content key for a package's native artifact.
+#
+# The key is a fingerprint of the Rust SOURCE inputs that determine the built
+# binary — NOT the binary itself (the compiled xcframework is non-reproducible:
+# embedded timestamps + build paths, see .gitignore). Producer and consumer both
+# derive the key from the same committed source, so they agree on which asset to
+# publish / fetch without trusting any binary hash.
+#
+# Usage:  scripts/artifact-key.sh <package-dir> <target>
+#         scripts/artifact-key.sh packages/chat-mls-core ios
+#
+# No git dependency (runs on the EAS builder, which unpacks a tarball, not a
+# repo) — resolves the repo root relative to this script.
+set -euo pipefail
+
+PKG="${1:?usage: artifact-key.sh <package-dir> <ios|android>}"
+TARGET="${2:?usage: artifact-key.sh <package-dir> <ios|android>}"
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$ROOT"
+
+[ -d "$PKG" ] || { echo "artifact-key: no such package dir: $PKG" >&2; exit 2; }
+
+# Source set that feeds the native build. The `node/` subtree is a separate
+# napi crate (not linked into the iOS xcframework), so it's excluded.
+list_inputs() {
+  printf '%s\n' \
+    "$PKG/Cargo.toml" \
+    "$PKG/Cargo.lock" \
+    "$PKG/scripts/build-mls.sh"
+  find "$PKG/src" -type f -name '*.rs' 2>/dev/null
+}
+
+# Hash each input's contents, then hash the sorted list of (hash, path) pairs.
+# LC_ALL=C keeps sort order stable across machines. Target is folded in so
+# ios/android keys differ even for identical source.
+KEY="$(
+  {
+    printf 'target=%s\n' "$TARGET"
+    list_inputs | LC_ALL=C sort -u | while IFS= read -r f; do
+      [ -f "$f" ] && shasum -a 256 "$f"
+    done
+  } | shasum -a 256 | awk '{print $1}'
+)"
+
+# 16 hex chars — collision-safe for this scale, filename-friendly.
+echo "${KEY:0:16}"
diff --git a/scripts/fetch-native-artifacts.sh b/scripts/fetch-native-artifacts.sh
new file mode 100755
index 0000000..6e48d09
--- /dev/null
+++ b/scripts/fetch-native-artifacts.sh
@@ -0,0 +1,109 @@
+#!/usr/bin/env bash
+# Restore a package's gitignored native binary from R2 and verify it against the
+# committed checksum manifest. Runs as the EAS `eas-build-pre-install` hook (on
+# Expo's builder, before `pod install`) and anywhere else the xcframework binary
+# is needed but not in git.
+#
+# Contract (see docs/adr — non-reproducible binaries → CI is the sole builder):
+#   * The Mach-O binary inside chat_mls_coreFFI.xcframework is gitignored (too
+#     large + non-reproducible). Headers/plist/modulemap + the .sha256 manifest
+#     + .artifact-key ARE committed.
+#   * The producer workflow (native-artifacts.yml) builds the xcframework,
+#     uploads it to R2 keyed by the source fingerprint, and commits the
+#     refreshed manifest + .artifact-key. That published asset is what this
+#     script fetches, so asset ↔ manifest always match.
+#
+# Usage:  scripts/fetch-native-artifacts.sh <ios|android>
+#
+# Env:
+#   R2_PUBLIC_BASE_URL   (required) public-read base, e.g.
+#                        https://native.example.com/mortstack — asset is
+#                        fetched from "$R2_PUBLIC_BASE_URL/<asset>".
+#   ALLOW_BUILD=1        (optional) on cache-miss, compile from source instead
+#                        of failing. For local dev only — the EAS builder has no
+#                        Rust toolchain, so it must hit the fast fetch path.
+set -euo pipefail
+
+TARGET="${1:?usage: fetch-native-artifacts.sh <ios|android>}"
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$ROOT"
+
+# ── Artifact registry ─────────────────────────────────────────────────────────
+# Extend with new rows as android AAR / chat-crypto SignalFfi come online.
+case "$TARGET" in
+  ios)
+    PKG="packages/chat-mls-core"
+    DEST_DIR="$PKG/ios"
+    XCF="chat_mls_coreFFI.xcframework"
+    MANIFEST="$XCF.sha256"                 # relative to $DEST_DIR
+    ASSET_PREFIX="chat_mls_coreFFI-ios"
+    BUILD_SCRIPT_TARGET="ios"
+    ;;
+  android)
+    # TODO: android jniLibs (*.so) are gitignored too — same trap, not yet
+    # published to R2. Soft no-op so android EAS builds aren't blocked by this
+    # hook until the AAR pipeline is wired. Wire it here when ready.
+    echo "native(android): AAR pipeline not yet published via R2 — skipping"
+    exit 0
+    ;;
+  *)
+    echo "fetch-native-artifacts: unsupported target '$TARGET'" >&2
+    exit 2
+    ;;
+esac
+
+# Verify the extracted tree against the committed manifest. hash_dir wrote paths
+# relative to the xcframework dir, so we cd into it and point at ../<manifest>.
+verify() {
+  ( cd "$DEST_DIR/$XCF" && shasum -a 256 -c "../$MANIFEST" ) >/dev/null 2>&1
+}
+
+# Already present and valid (warm builder / re-run)? Nothing to do.
+if [ -f "$DEST_DIR/$XCF/Info.plist" ] && verify; then
+  echo "native($TARGET): $XCF present + verified — skip"
+  exit 0
+fi
+
+KEY="$(bash scripts/artifact-key.sh "$PKG" "$TARGET")"
+ASSET="${ASSET_PREFIX}-${KEY}.tar.gz"
+
+fetch() {
+  local base="${R2_PUBLIC_BASE_URL:?set R2_PUBLIC_BASE_URL (public R2 base URL)}"
+  local url="${base%/}/$ASSET"
+  local tmp; tmp="$(mktemp -d)"; trap 'rm -rf "$tmp"' RETURN
+  echo "native($TARGET): fetching $url"
+  curl -fSL --retry 3 --retry-delay 2 -o "$tmp/a.tgz" "$url" || return 1
+  tar xzf "$tmp/a.tgz" -C "$DEST_DIR"
+}
+
+if fetch && verify; then
+  echo "native($TARGET): fetched + verified ($ASSET)"
+  exit 0
+fi
+
+# Extracted but checksum failed = corruption/tamper or stale asset ≠ manifest.
+if [ -f "$DEST_DIR/$XCF/Info.plist" ] && ! verify; then
+  echo "native($TARGET): CHECKSUM MISMATCH — $ASSET does not match committed $MANIFEST" >&2
+fi
+
+# ── Fallback ──────────────────────────────────────────────────────────────────
+if [ "${ALLOW_BUILD:-0}" = "1" ]; then
+  echo "native($TARGET): asset missing/invalid — building from source (ALLOW_BUILD=1)"
+  pnpm --filter @repo/chat-mls-core "build:${BUILD_SCRIPT_TARGET}"
+  verify && { echo "native($TARGET): built + verified"; exit 0; }
+  echo "native($TARGET): local build produced a tree that fails $MANIFEST" >&2
+  exit 1
+fi
+
+cat >&2 <<EOF
+native($TARGET): artifact not available.
+  asset : $ASSET
+  key   : $KEY   (source fingerprint of $PKG)
+  base  : ${R2_PUBLIC_BASE_URL:-<unset>}
+
+The prebuilt xcframework for this source revision has not been published.
+  → Run the 'Native artifacts' workflow (Actions ▸ workflow_dispatch), or
+  → re-run locally with ALLOW_BUILD=1 to compile from source (needs Rust + Xcode).
+EOF
+exit 1