chat: tag OpenCode sessions with officer metadata (cwd) + filter lists by it

OpenCode has no per-session directory (every session runs in the fixed server's cwd),
so sessions from every context (/chat pwd, email account, project) all landed in one
list. Now each session is tagged on creation with its logical cwd via the free-form
session `metadata`: { officer: { cwd } } — API-settable, round-trips on list+detail,
never touched by opencode core (confirmed by source dive + live test).

- client.createSession(metadata?) sends `metadata`; adds OfficerSessionMeta + officerMeta() helper.
- send-opencode tags new sessions with { officer: { cwd } } (the resolved chat cwd).
- websocket: pass the full resolved cwd for every context (not just non-/chat).
- listOpenCodeSessions(cwd?) filters by metadata.officer.cwd; chat.ts passes the request cwd.

Verified live: sessions tagged with distinct cwds list only under their own cwd.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/servers/channels/send-opencode.ts

@@ -45,7 +45,9 @@ export async function sendOpenCodeStreaming(params: OpenCodeStreamingParams): Pr
     (params.sessionKey.startsWith('ses_') ? params.sessionKey : undefined) ??
     params.resumeSessionId;
   if (!opencodeSessionId) {
-    opencodeSessionId = await conn.createSession(params.cwd);
+    // Tag the session with its logical cwd so it can be listed in the right place (OpenCode has no
+    // per-session directory — every session runs in the fixed server's cwd).
+    opencodeSessionId = await conn.createSession(params.cwd ? { officer: { cwd: params.cwd } } : undefined);
   }
   setOpenCodeSession(params.sessionKey, opencodeSessionId);
   const sessionId = opencodeSessionId;