fix(sync): route sessions by server-confirmed directory, unstick queued sends

Session directory resolution had no precedence contract: the selection-time
directory short-circuited every lookup, and a persisted runtime value was
consulted before the authoritative record. A worktree session selected before
its directory store bootstrapped kept the active-directory fallback, and that
guess was persisted, so it survived reloads and restarts.

Directory resolution now lives in one module and orders sources by whether the
server confirmed the path, not by whether the value is local or synced:
authoritative (the child store that holds the session) > server-confirmed
selection > worktree attachment/metadata (the requested path, pre-canonical) >
remembered. A guessed selection is no longer persisted, remembered, or ranked.
Chips read the same resolution the composer used, so queue keys cannot diverge.

Queued auto-send could strand an item indefinitely: backoff, missing send
configuration, and the recent-abort window all returned without scheduling a
wake-up, so the queue only retried when an unrelated status or directory change
re-ran the effect. A retry scheduler now wakes it at the earliest known time.

A rejected send rolls the optimistic message back while the composer stays
silent for transport failures, which makes it indistinguishable from nothing
happening. Failures are now recorded to a bounded in-memory log surfaced in the
About diagnostics report, alongside a directory-resolution breakdown, plus
__opencodeDebug.diagnoseSessionDirectory() and getRecentSendFailures().

Prompted by a report of worktree prompting silently failing. That failure was
not reproduced locally, so the diagnostics are what will identify it.

packages/ui/src/sync/sync-refs.ts

@@ -17,6 +17,7 @@ const configListeners = new Set<(directory: string, config: Config) => void>()
 let cachedSessionManager: ChildStoreManager | null = null
 let cachedSessionSlices = new Map<string, State["session"]>()
 let cachedSessionsById = new Map<string, State["session"][number]>()
+let cachedSessionDirectoryById = new Map<string, string>()
 
 export function setSyncRefs(
   _sdk: OpencodeClient,
@@ -29,6 +30,7 @@ export function setSyncRefs(
     cachedSessionManager = null
     cachedSessionSlices = new Map()
     cachedSessionsById = new Map()
+    cachedSessionDirectoryById = new Map()
   }
   _directory = directory
   if (registerSessionDirectory) {
@@ -103,20 +105,38 @@ export function getAllSyncSessionMap(): ReadonlyMap<string, State["session"][num
 
   const nextSlices = new Map<string, State["session"]>()
   const nextSessionsById = new Map<string, State["session"][number]>()
+  const nextDirectoriesById = new Map<string, string>()
   for (const [directory, store] of stores.children) {
     const sessions = store.getState().session
     nextSlices.set(directory, sessions)
     for (const session of sessions) {
       if (!session?.id) continue
       nextSessionsById.set(session.id, session)
+      nextDirectoriesById.set(session.id, directory)
     }
   }
   cachedSessionManager = stores
   cachedSessionSlices = nextSlices
   cachedSessionsById = nextSessionsById
+  cachedSessionDirectoryById = nextDirectoriesById
   return cachedSessionsById
 }
 
+/**
+ * Directory of the child store that actually holds this session.
+ *
+ * This is the authoritative session→directory mapping: a session is present in
+ * exactly the store for the directory it belongs to, regardless of whether the
+ * server populated `session.directory` on the record itself. Returns `null`
+ * when no initialized child store contains the session, which means "unknown",
+ * never "no directory".
+ */
+export function getSyncSessionDirectory(sessionId: string): string | null {
+  if (!sessionId) return null
+  getAllSyncSessionMap()
+  return cachedSessionDirectoryById.get(sessionId) ?? null
+}
+
 /** Read messages for a session from current directory's child store */
 export function getSyncMessages(sessionId: string, directory?: string) {
   return getDirectoryState(directory)?.message[sessionId] ?? []