feat: model lists and prices that follow each AI tool, a Settings tab per tool, live lane status (#40)

Pricing: the LiteLLM sync now adds every current Claude / GPT (>= 5) /
Gemini (>= 3) chat model before it is used and keeps its own rows
(model_pricing.source = 'sync', the Auto badge) at the published rate. A
user's row (any PUT) and a deleted pattern (model_pricing_dismissed) are
never touched; a deleted built-in row is not re-seeded at the next start; a
reset re-applies the list at once; retired Claude models are priced only
once used.

Models: GET /api/ai-tools/:id/models reads each tool's own list (Codex's
models_cache.json, Claude's aliases named after the newest version plus
priced versions, a catalog tool's vendor rows plus the models its sessions
used). A catalog `model: {flag, vendor?}` field passes `<flag> <id>`
(validated: never a flag or shell text); a per-tool default model starts
each run, and a resume keeps the session's own model.

Settings: every installed, enabled catalog tool without its own tab gets
one (AiToolConfig.tsx): path, homepage, Update, sessions/cost/lanes,
default model, vendor pricing, and the config files its release catalog
lists, edited over the opened sha, syntax-checked, backed up, written
atomically; credential-looking names refused. Antigravity keeps its hooks
card there.

Lanes: a just-started run no longer reads "dead" (age counts the run's
start while the old session is still bound); a second dashboard on the
same database re-broadcasts the lanes the other changed (PRAGMA
data_version, every 2 s); a lane start with a bad model answers 400.

DB: every migration runs under a cross-process lock (<db>-migrate.lock), so
two dashboards started at once on a fresh database both come up.

client/src/hooks/useAiTools.ts

@@ -8,7 +8,7 @@
  */
 
 import { useEffect, useSyncExternalStore } from "react";
-import { api, type AiTool, type AiToolsView } from "../lib/api";
+import { api, type AiTool, type AiToolUpdateBody, type AiToolsView } from "../lib/api";
 
 let view: AiToolsView | null = null;
 let inflight: Promise<void> | null = null;
@@ -74,7 +74,7 @@ export function useAiTools() {
     label: (id: string) => byId(id)?.label ?? FALLBACK[id] ?? id,
     reload: load,
     refresh: async () => publish(await api.aiTools.refresh()),
-    update: async (id: string, body: { enabled?: boolean; default?: true }) =>
+    update: async (id: string, body: AiToolUpdateBody) =>
       publish(await api.aiTools.update(id, body)),
   };
 }