v1.12.1: rich status indicator + server-side workspace pane sync

Status indicator (StatusDot): drops the flat amber pulse for a richer set
of states — orbiting amber for streaming, spinning sky ring for tool_running,
static violet for waiting_for_input, plus the existing idle/error. Backend
chat_status frame widens from 'working|idle|error' to discriminate streaming
vs tool execution vs paused for user input.

Workspace pane sync: pane layout moves from per-device localStorage to
server-side sessions.workspace_panes jsonb. PATCH /api/sessions/:id/workspace
broadcasts session_workspace_updated on the user channel for cross-device live
sync. Echo dedup via JSON comparison so the round-trip frame doesn't loop.
Legacy localStorage seeds the server on first hydrate, then is deleted.
Deprecated session_panes table dropped.

Resilience: startup sweep marks any stale 'streaming' message older than
5 minutes as 'failed' so v1.12.0-style hung rows clear on container restart.
useWorkspacePanes gains validatePanes() to prune dead chatId references from
saved pane state when the chat list lands.

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

apps/server/src/index.ts

@@ -49,6 +49,18 @@ async function main() {
   await applySchema(sql);
   app.log.info('database schema applied');
 
+  const swept = await sql<{ count: string }[]>`
+    WITH swept AS (
+      UPDATE messages SET status = 'failed'
+      WHERE status = 'streaming' AND created_at < NOW() - INTERVAL '5 minutes'
+      RETURNING id
+    ) SELECT count(*)::text AS count FROM swept
+  `;
+  const sweptCount = Number(swept[0]?.count ?? 0);
+  if (sweptCount > 0) {
+    app.log.info({ sweptCount }, 'swept stale streaming messages to failed');
+  }
+
   // v1.11.3: tell the model-context cache where llama-swap lives. Cache
   // lookups go to ${LLAMA_SWAP_URL}/upstream/<model>/props to read
   // default_generation_settings.n_ctx — the value persisted as messages.ctx_max.