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/client/src/i18n/locales/de.ts

@@ -61,6 +61,7 @@ export default {
 
   // Chat
   chat: {
+    contextRemaining: 'übrig',
     emptyState: 'Starten Sie eine Konversation mit Hermes Agent',
     inputPlaceholder: 'Nachricht eingeben... (Enter zum Senden, Shift+Enter fur neue Zeile)',
     attachFiles: 'Dateien anhangen',

packages/client/src/i18n/locales/en.ts

@@ -73,6 +73,7 @@ export default {
 
   // Chat
   chat: {
+    contextRemaining: 'remaining',
     emptyState: 'Start a conversation with Hermes Agent',
     inputPlaceholder: 'Type a message... (Enter to send, Shift+Enter for new line)',
     attachFiles: 'Attach files',

packages/client/src/i18n/locales/es.ts

@@ -61,6 +61,7 @@ export default {
 
   // Chat
   chat: {
+    contextRemaining: 'restante',
     emptyState: 'Inicia una conversacion con Hermes Agent',
     inputPlaceholder: 'Escribe un mensaje... (Enter para enviar, Shift+Enter para nueva linea)',
     attachFiles: 'Adjuntar archivos',

packages/client/src/i18n/locales/fr.ts

@@ -61,6 +61,7 @@ export default {
 
   // Chat
   chat: {
+    contextRemaining: 'restant',
     emptyState: 'Demarrer une conversation avec Hermes Agent',
     inputPlaceholder: 'Tapez un message... (Entree pour envoyer, Shift+Entree pour un saut de ligne)',
     attachFiles: 'Joindre des fichiers',

packages/client/src/i18n/locales/ja.ts

@@ -61,6 +61,7 @@ export default {
 
   // チャット
   chat: {
+    contextRemaining: '残り',
     emptyState: 'Hermes Agent と会話を開始しましょう',
     inputPlaceholder: 'メッセージを入力... (Enter で送信、Shift+Enter で改行)',
     attachFiles: 'ファイルを添付',

packages/client/src/i18n/locales/ko.ts

@@ -61,6 +61,7 @@ export default {
 
   // 채팅
   chat: {
+    contextRemaining: '남음',
     emptyState: 'Hermes Agent와 대화를 시작하세요',
     inputPlaceholder: '메시지를 입력하세요... (Enter로 전송, Shift+Enter로 줄바꿈)',
     attachFiles: '파일 첨부',

packages/client/src/i18n/locales/pt.ts

@@ -61,6 +61,7 @@ export default {
 
   // Chat
   chat: {
+    contextRemaining: 'restante',
     emptyState: 'Inicie uma conversa com o Hermes Agent',
     inputPlaceholder: 'Digite uma mensagem... (Enter para enviar, Shift+Enter para nova linha)',
     attachFiles: 'Anexar arquivos',

packages/client/src/i18n/locales/zh.ts

@@ -73,6 +73,7 @@ export default {
 
   // 对话
   chat: {
+    contextRemaining: '剩余',
     emptyState: '开始与 Hermes Agent 对话',
     inputPlaceholder: '输入消息... (Enter 发送，Shift+Enter 换行)',
     attachFiles: '添加附件',