Phase 7: Bot/extension system

Bot accounts (User rows with is_bot=True), scoped API tokens (read:messages,
write:messages, manage:rooms) authenticated via Authorization: Bearer on both
REST and the WS handshake, live bot WebSocket access on the same /ws/chat
endpoint humans use, message editing (WS "edit" envelope -> message_update
broadcast, fans out cross-instance for free via the existing broadcaster),
incoming webhooks (room-scoped, no auth beyond the URL token), and outgoing
webhooks/event subscriptions (HMAC-SHA256 signed, backgrounded delivery,
creation-time SSRF validation against private/loopback/link-local targets).

Token auth is additive, not a parallel system: a bearer-token-authenticated
bot goes through the exact same room-membership/role checks a session-
authenticated human does everywhere; only read:messages/write:messages are
separately scope-gated (the two message endpoints). manage:rooms scope
enforcement, full per-delivery SSRF re-validation, and bot API rate limiting
were explicitly scoped out (confirmed with the repo owner) as disproportionate
to this phase -- documented as known gaps in backend/README.md rather than
silently skipped.

Admin portal gains a Bots tab (create bots, issue/revoke scoped tokens,
cross-room webhook visibility); RoomInfoPanel gains room-scoped webhook/
subscription management, mirroring how invites already work there. The chat
UI also gets a minimal "edit your own message" affordance -- not asked for
by the issue, but the only practical way to exercise the edit pipeline by
hand instead of only via a scripted bot client.

Along the way: fixed a real bug caught while writing the incoming-webhook
test -- offline-push notification relied on the sender being "connected" to
exclude themselves, true for WS-originated messages but not for the new
webhook path, which has no WS connection for the attributed sender at all.
Now explicitly excluded. Also discovered the REST-only test fixture never
triggered ASGI lifespan, so app.state.broadcaster/presence didn't exist for
it; moved their construction out of the lifespan into create_app() itself
(Redis client construction is synchronous/lazy) so both the WS and
REST-only paths always have them.

New tests/test_bots.py, test_message_edit.py, test_webhooks.py (full suite
now 78/78, stable across repeated runs) plus a scripted end-to-end smoke
test (bot WS join/post/edit, incoming webhook, SSRF rejection, outgoing
delivery) and a full browser walkthrough of the new admin/room UI.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/components/ChatPane.tsx

@@ -43,6 +43,17 @@ export function ChatPane({ room, members, isMobile, onBack, onToggleInfo, infoOp
   const onMessage = useCallback((envelope: ServerEnvelope) => {
     if (envelope.type === 'message') {
       setLive((prev) => [...prev, envelope])
+    } else if (envelope.type === 'message_update') {
+      setHistory((prev) =>
+        prev.map((m) =>
+          m.id === envelope.id ? { ...m, content: envelope.content, edited_at: envelope.edited_at } : m,
+        ),
+      )
+      setLive((prev) =>
+        prev.map((m) =>
+          m.id === envelope.id ? { ...m, content: envelope.content, edited_at: envelope.edited_at } : m,
+        ),
+      )
     } else if (envelope.type === 'error') {
       setWsError(envelope.detail)
     }
@@ -50,7 +61,7 @@ export function ChatPane({ room, members, isMobile, onBack, onToggleInfo, infoOp
 
   const onUnauthenticated = useCallback(() => navigate('/login'), [navigate])
 
-  const { connected, send } = useChatSocket({ roomId: room.id, onMessage, onUnauthenticated })
+  const { connected, send, sendEdit } = useChatSocket({ roomId: room.id, onMessage, onUnauthenticated })
 
   return (
     <section className="chat-pane">
@@ -88,7 +99,7 @@ export function ChatPane({ room, members, isMobile, onBack, onToggleInfo, infoOp
         </p>
       )}
 
-      <MessageList messages={[...history, ...live]} members={members} />
+      <MessageList messages={[...history, ...live]} members={members} onEdit={sendEdit} />
       <Composer roomName={room.name} disabled={!connected} onSend={send} />
     </section>
   )