batch4: chats-in-sessions, force-send, /compact, right-rail file browser

Session 1:N Chat data model with backfill. Workspace switches to client-side
multi-tab pane management. Right-rail file browser with float-over viewer and
click-drag line selection replaces FileBrowserPane. Adds /compact streaming
summarizer (respects compact markers in context builder), force-send (cancels
in-flight, persists partial as 'cancelled', awaits cancellation completion via
deferred Promise + 5s timeout), message queue, stop generation, chat
auto-rename, session archive/unarchive with Closed Sessions section on repo
landing page. CHECK constraints on sessions.status, messages.role,
messages.status with KEEP IN SYNC comments tying to MESSAGE_ROLES /
MESSAGE_STATUSES const arrays. Deletes dead pane routes/hook and the
api.panes.* client block.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/src/components/MessageList.tsx

@@ -1,13 +1,13 @@
 import { useEffect, useRef } from 'react';
-import type { Message } from '@/api/types';
+import type { Chat, Message } from '@/api/types';
 import { MessageBubble } from './MessageBubble';
 
 interface Props {
   messages: Message[];
-  sessionId: string;
+  sessionChats?: Chat[];
 }
 
-export function MessageList({ messages, sessionId }: Props) {
+export function MessageList({ messages, sessionChats }: Props) {
   const endRef = useRef<HTMLDivElement>(null);
 
   useEffect(() => {
@@ -25,7 +25,7 @@ export function MessageList({ messages, sessionId }: Props) {
   return (
     <div className="flex-1 overflow-y-auto px-6 py-4 space-y-4">
       {messages.map((m) => (
-        <MessageBubble key={m.id} message={m} sessionId={sessionId} />
+        <MessageBubble key={m.id} message={m} sessionChats={sessionChats} />
       ))}
       <div ref={endRef} />
     </div>