merge: integrate origin/main (406 commits) into live branch

Merge upstream's paired-room stabilization, dedicated message-runtime-loop,
outbound delivery refactor (ipc-outbound-delivery / deliverFormattedCanonicalMessage),
discord module split, dashboard rework, and migrations 015-018 into our branch.

Conflict policy: prefer upstream for the heavily-refactored paired-room /
message-runtime / db cluster (it supersedes our earlier loop band-aids), keep
only orthogonal unique fixes:
- codex bundled-JS launcher fix (codex-warmup.ts)
- slot-aligned Claude+Codex usage primer (usage-primer.ts) re-wired into index.ts
- MemoryHigh=3G cgroup bound, discord perms diagnostic, prompt docs
- progress null-race + silent-failure publish guards (message-turn-controller.ts)

Dropped (superseded by upstream or unwired): reviewer STEP_DONE/TASK_DONE loop
band-aids, router markdown-escape override, register tribunal-default+git-init,
restart-context rewindToSeq (unwired).

Verified: typecheck clean, build clean, vitest shows zero new regressions vs the
origin/main baseline (only pre-existing env-config failures remain).

src/db/base-schema.ts

@@ -1,5 +1,25 @@
 import { Database } from 'bun:sqlite';
 
+const ROOM_SKILL_OVERRIDES_SCHEMA = `
+  CREATE TABLE IF NOT EXISTS room_skill_overrides (
+    chat_jid TEXT NOT NULL,
+    agent_type TEXT NOT NULL,
+    skill_scope TEXT NOT NULL,
+    skill_name TEXT NOT NULL,
+    enabled INTEGER NOT NULL,
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    PRIMARY KEY (chat_jid, agent_type, skill_scope, skill_name),
+    FOREIGN KEY (chat_jid) REFERENCES room_settings(chat_jid) ON DELETE CASCADE,
+    CHECK (agent_type IN ('claude-code', 'codex')),
+    CHECK (enabled IN (0, 1)),
+    CHECK (length(skill_scope) > 0),
+    CHECK (length(skill_name) > 0)
+  );
+  CREATE INDEX IF NOT EXISTS idx_room_skill_overrides_room
+    ON room_skill_overrides(chat_jid, agent_type);
+`;
+
 export function applyBaseSchema(database: Database): void {
   database.exec(`
     CREATE TABLE IF NOT EXISTS chats (
@@ -24,6 +44,7 @@ export function applyBaseSchema(database: Database): void {
       FOREIGN KEY (chat_jid) REFERENCES chats(jid)
     );
     CREATE INDEX IF NOT EXISTS idx_timestamp ON messages(timestamp);
+    CREATE INDEX IF NOT EXISTS idx_messages_chat_timestamp ON messages(chat_jid, timestamp DESC);
     CREATE TABLE IF NOT EXISTS message_sequence (
       id INTEGER PRIMARY KEY AUTOINCREMENT
     );
@@ -160,7 +181,7 @@ export function applyBaseSchema(database: Database): void {
       task_id TEXT NOT NULL,
       turn_number INTEGER NOT NULL,
       role TEXT NOT NULL,
-      output_text TEXT NOT NULL,
+      output_text TEXT NOT NULL, attachment_payload TEXT,
       verdict TEXT,
       created_at TEXT NOT NULL,
       UNIQUE(task_id, turn_number, role)
@@ -410,8 +431,7 @@ export function applyBaseSchema(database: Database): void {
       last_used_at TEXT,
       archived_at TEXT
     );
-    CREATE INDEX IF NOT EXISTS idx_memories_scope
-      ON memories(scope_kind, scope_key);
+    CREATE INDEX IF NOT EXISTS idx_memories_scope ON memories(scope_kind, scope_key);
     CREATE INDEX IF NOT EXISTS idx_memories_active
       ON memories(scope_kind, scope_key, archived_at, created_at);
     CREATE VIRTUAL TABLE IF NOT EXISTS memories_fts USING fts5(
@@ -435,4 +455,5 @@ export function applyBaseSchema(database: Database): void {
       VALUES (new.id, new.content, new.keywords_json);
     END;
   `);
+  database.exec(ROOM_SKILL_OVERRIDES_SCHEMA);
 }