M3: channels/threads + cron delivery + search + outbox sync

Gateway plugin:
- ChannelDirectory (SQLite): channels + threads, friendly-name resolution
- FTS5 search bridge over state.db (scope all/chat, LIKE fallback)
- Outbox (monotonic cursor, 72h retention) for reconnect catch-up
- adapter: channel.* handlers, search, sync, cron target parsing
- ws_server: M3 frame routing + hello.ack sync cursor

App (KMP):
- ChannelStore (directory cache) + lane-aware ChatStore (per chat/thread)
- GatewayClient.sendFrame; IrisController channel/search/nav actions
- ChatScreen: channel drawer, thread toggle, topic switcher, search overlay

.gitignore

@@ -13,6 +13,7 @@ venv/
 
 # ── Kotlin / Gradle (app) ─────────────────────────────────────────────────
 .gradle/
+.kotlin/
 build/
 local.properties
 *.iml