[Bug]: OpenCode provider overwrites user-set thread titles repeatedly (provider title mirror bypasses canReplaceThreadTitle)

[JorgeMenaDev]

What happens

A thread backed by the OpenCode provider has its user-set title repeatedly overwritten with OpenCode's auto-generated session title. I create a thread with an explicit title (thread.create with title), never send titleSeed or regenerateTitle, and the title is replaced within seconds — and then again, and again. Measured 13 and 38 overwrites on two threads in a single session.

thread.meta.update (the "rename" path) does hold the title, but only until the next provider event, so re-asserting it is a race that can't be won.

Threads on claudeAgent, grok and cursor keep their titles correctly. Only OpenCode (and, more quietly, Codex) is affected.

Root cause

canReplaceThreadTitle (apps/server/src/orchestration/Layers/ProviderCommandReactor.ts:165) is not on this code path. Its only two call sites (:1052, :800) gate T3's own first-turn title generator. The provider-title mirror never consults it:

1. apps/server/src/provider/Layers/OpenCodeAdapter.ts:199-205 reads title from every OpenCode session.updated event.
2. OpenCodeAdapter.ts:785-825 emits it as thread.metadata.updated with payload.name, guarded only by if (title).
3. apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.ts:1707-1714 dispatches that straight into thread.meta.update — no guard, no dedup, no comparison against the thread's current title:

if (event.type === "thread.metadata.updated" && event.payload.name) {
  yield* orchestrationEngine.dispatch({
    type: "thread.meta.update",
    commandId: yield* providerCommandId(event, "thread-meta-update"),
    threadId: thread.id,
    title: event.payload.name,
  });
}

The repetition count comes from the OpenCode side: OpenCode's patch() publishes session.updated carrying the entire session record — including title — on every session mutation, including touch() on each prompt (packages/opencode/src/session/session.ts:735, :752). Their sync layer documents this as deliberate back-compat behaviour. So one generated title gets re-applied on every unrelated session change.

ClaudeAdapter, GrokAdapter and CursorAdapter never emit thread.metadata.updated, which is exactly why their titles survive. CodexAdapter.ts:712-732 has the same unguarded path but fires only on the dedicated, infrequent thread/name/updated notification.

Also relevant: T3 never gives OpenCode a title. OpenCodeAdapter.ts:1303-1312 calls client.session.create({ permission }) with no title, so OpenCode auto-names the session and T3 mirrors that name back onto a thread the user already named.

Suggested fix

Two options, not mutually exclusive:

1. Pass the thread title at session creation (smallest, no behaviour change elsewhere). OpenCode's CreateInput accepts title (packages/opencode/src/session/session.ts:260-270), and its titler backs off from any non-default title (packages/opencode/src/session/prompt.ts:199-200, isDefaultTitle). Sending the title at OpenCodeAdapter.ts:1303 means OpenCode never generates one and the mirror becomes a self-consistent no-op.

2. Guard the shared mirror at ProviderRuntimeIngestion.ts:1707 with canReplaceThreadTitle (currently module-private in ProviderCommandReactor.ts). ~5 lines, and it closes the same hole for Codex — though that is a deliberate semantic call, since a Codex thread would stop following Codex-side renames once T3 has a non-default title.

A titleLocked / titleSource field, or an expectedTitle compare-and-swap on thread.meta.update (mirroring the existing expectedBranch at apps/server/src/orchestration/decider.ts:639-644), would be the more thorough fix — there is currently no way for any client to express "this title is mine". Grepping titleLocked|userTitle|pinnedTitle|titleSource|titleOwner returns zero matches.

Steps to reproduce

1. Create a thread on an OpenCode instance with an explicit non-default title (e.g. My custom name).
2. Send it a prompt.
3. Watch the sidebar: the title is replaced by OpenCode's generated name, and re-replaced on each subsequent session mutation.
4. Renaming the thread manually holds only until the next provider event.

Version

Reproduced on nightly v0.0.32-nightly.20260802.980. Code references above are from commit e60821f0e0d82a5d671ca3b94719c49d333921c8. OpenCode side read at anomalyco/opencode@1882c33; running opencode binary reports 1.18.11.