docs(cli): state the measured compose default instead of a paraphrased quote (#8343)

The card quoted the EE compose file as documenting `OS_CLOUD_URL=off` for
完全自托管. That phrase appears nowhere in the cloud repo — it is the
reporter's paraphrase, so it had no business sitting in a code comment as
a quotation. What the file actually says is stronger and checkable:
`OS_CLOUD_URL: ${OS_CLOUD_URL:-off}`, i.e. `off` is the SHIPPED DEFAULT,
so every self-hosted stack that does not override it hit this bug.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016pY4Xb2iDecfDtT3CWoiTW

Author: claude

.changeset/tidy-donkeys-shave.md

@@ -4,7 +4,7 @@
 
 `objectstack serve` now mounts the local-install surface on a runtime with the cloud switched off (#8343).
 
-`OS_CLOUD_URL=off` — the value the self-hosted EE compose file documents for a fully self-hosted box — used to skip the entire marketplace wiring block, including `MarketplaceInstallLocalPlugin`. That plugin serves `os package install ./dist/objectstack.json`, the documented air-gapped path, whose inline-manifest branch reads no cloud URL at all. The result, measured on a customer deployment: `GET` and `POST /api/v1/marketplace/install-local` both 404 with no other package-install surface available, so the deployment could not install a package by any route.
+`OS_CLOUD_URL=off` — the value the self-hosted EE image's compose file ships as its default (`${OS_CLOUD_URL:-off}`) — used to skip the entire marketplace wiring block, including `MarketplaceInstallLocalPlugin`. That plugin serves `os package install ./dist/objectstack.json`, the documented air-gapped path, whose inline-manifest branch reads no cloud URL at all. The result, measured on a customer deployment: `GET` and `POST /api/v1/marketplace/install-local` both 404 with no other package-install surface available, so the deployment could not install a package by any route.
 
 The registration condition is now split by what each surface actually needs. The control-plane clients (marketplace browse proxy, cloud-connection, pushed runtime-config) still require a resolved cloud URL; the local install surface mounts regardless, pinned to no control plane so its catalog branch answers `503 MARKETPLACE_UNAVAILABLE` locally rather than dialling out. A host config that wires its own install-local keeps it, and the runtime host-kernel skip is unchanged.
 

packages/cli/src/commands/serve.ts

@@ -1772,10 +1772,12 @@ export default class Serve extends Command {
       // hands the compiled artifact over inline, and `handleInstall`'s inline
       // branch never reads `this.cloudUrl` at all — so gating it on a control
       // plane withheld it from the one deployment that cannot have one. A
-      // self-hosted EE box (whose compose file documents `OS_CLOUD_URL=off`
-      // for 完全自托管) could not install a package by ANY route: measured on
-      // objectos-ee 4.0.5-rc.1, both GET and POST /marketplace/install-local
+      // self-hosted EE box could not install a package by ANY route: measured
+      // on objectos-ee 4.0.5-rc.1, both GET and POST /marketplace/install-local
       // 404, while its own /runtime/config advertised `installLocal: true`.
+      // Note `off` is not an unusual choice there but the SHIPPED DEFAULT --
+      // that image's compose file reads `OS_CLOUD_URL: ${OS_CLOUD_URL:-off}`,
+      // so every self-hosted stack that does not override it landed here.
       // The package README states the intended contract in as many words —
       // "`OS_CLOUD_URL=off` disables every remote call; air-gapped installs
       // keep working via inline manifests handed to `install-local`" — so the