feat: add token usage tracking, context display, and dynamic context length (#132)

* fix: specify TS_NODE_PROJECT for dev:server script

ts-node/register resolves tsconfig from the entry file upward,
finding the root solution-style tsconfig.json (no compilerOptions).
This causes target to default to ES3, breaking MapIterator spread
syntax (TS2802). Set TS_NODE_PROJECT env var to point to the server
tsconfig which targets ES2024.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* feat: add token usage tracking, context display, and dynamic context length

- Intercept SSE proxy to capture run.completed events and persist token
  usage (input_tokens, output_tokens) per session to SQLite/JSON store
- Display context usage bar in ChatInput showing used/total/remaining tokens
- Resolve actual context length from Hermes models_dev_cache.json based
  on the active profile's default model (fallback 200K), with 5min in-memory cache
- Move sessions-db.ts to db/hermes/ for unified database layer
- Add usage store with SQLite + JSON fallback (auto-migration via ensureTable)
- Fix proxy SSE path regex to match rewritten upstream path
- Fix route ordering: /sessions/usage before /sessions/:id to avoid 404
- Fetch per-session usage on session enter instead of batch
- Add unit tests for usage-store, db index, and proxy SSE interception

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

packages/server/src/index.ts

@@ -20,7 +20,7 @@ import { logger } from './services/logger'
 declare const __APP_VERSION__: string
 const APP_VERSION = typeof __APP_VERSION__ !== 'undefined'
   ? __APP_VERSION__
-  : (() => { try { return JSON.parse(readFileSync(resolve(__dirname, '../../package.json'), 'utf-8')).version } catch { return 'dev' } } )()
+  : (() => { try { return JSON.parse(readFileSync(resolve(__dirname, '../../package.json'), 'utf-8')).version } catch { return 'dev' } })()
 
 // Global error handlers
 process.on('uncaughtException', (err) => {
@@ -44,6 +44,12 @@ export async function bootstrap() {
 
   await initGatewayManager()
   console.log('[bootstrap] gateway manager initialized')
+
+  // Initialize web-ui SQLite tables
+  const { initUsageStore } = await import('./db/hermes/usage-store')
+  initUsageStore()
+  console.log('[bootstrap] usage store initialized')
+
   app.use(cors({ origin: config.corsOrigins }))
   app.use(bodyParser())
   console.log('[bootstrap] cors + bodyParser registered')