fix(dashboard): include cache tokens in totals, track real API call count

The analytics dashboard had three accuracy issues:

1. TOTAL TOKENS excluded cache_read and cache_write tokens — only counted
   the non-cached input portion. With 90%+ cache hit rates typical in
   Hermes, this dramatically undercounted actual token usage (e.g. showing
   9.1M when the real total was 169M+).

2. The 'API Calls' card displayed session count (COUNT(*) from sessions
   table), not actual LLM API requests. A single session makes 10-90 API
   calls through the tool loop, so this was ~30x lower than reality.

3. cache_write_tokens was stored in the DB but never exposed through the
   analytics API endpoint or frontend.

Changes:
- Add api_call_count column to sessions table (schema v7 migration)
- Persist api_call_count=1 per LLM API call in run_agent.py
- Analytics SQL queries now include cache_write_tokens and api_call_count
  in daily, by_model, and totals aggregations
- Frontend TOTAL TOKENS card now shows input + cache_read + cache_write +
  output (the full prompt total + output)
- API CALLS card now uses real api_call_count from DB
- New Cache Hit Rate card shows cache efficiency percentage
- Bar chart, tooltips, daily table, model table all use prompt totals
  (input + cache_read + cache_write) instead of just input
- Labels changed from 'Input' to 'Prompt' to reflect the full prompt total
- TypeScript interfaces and i18n strings updated (en + zh)

tests/hermes_cli/test_web_server.py

@@ -694,6 +694,8 @@ class TestNewEndpoints:
         assert "totals" in data
         assert isinstance(data["daily"], list)
         assert "total_sessions" in data["totals"]
+        assert "total_cache_write" in data["totals"]
+        assert "total_api_calls" in data["totals"]
 
     def test_session_token_endpoint_removed(self):
         """GET /api/auth/session-token no longer exists."""

tests/test_hermes_state.py

@@ -62,6 +62,27 @@ class TestSessionLifecycle:
         assert session["input_tokens"] == 300
         assert session["output_tokens"] == 150
 
+    def test_update_token_counts_tracks_api_call_count(self, db):
+        """api_call_count increments with each update_token_counts call."""
+        db.create_session(session_id="s1", source="cli")
+        db.update_token_counts("s1", input_tokens=100, output_tokens=50, api_call_count=1)
+        db.update_token_counts("s1", input_tokens=100, output_tokens=50, api_call_count=1)
+        db.update_token_counts("s1", input_tokens=100, output_tokens=50, api_call_count=1)
+
+        session = db.get_session("s1")
+        assert session["api_call_count"] == 3
+
+    def test_update_token_counts_api_call_count_absolute(self, db):
+        """absolute mode sets api_call_count directly."""
+        db.create_session(session_id="s1", source="cli")
+        db.update_token_counts("s1", input_tokens=100, output_tokens=50, api_call_count=1)
+        db.update_token_counts("s1", input_tokens=300, output_tokens=150,
+                               api_call_count=5, absolute=True)
+
+        session = db.get_session("s1")
+        assert session["api_call_count"] == 5
+        assert session["input_tokens"] == 300
+
     def test_update_token_counts_backfills_model_when_null(self, db):
         db.create_session(session_id="s1", source="telegram")
         db.update_token_counts("s1", input_tokens=10, output_tokens=5, model="openai/gpt-5.4")
@@ -935,7 +956,7 @@ class TestSchemaInit:
     def test_schema_version(self, db):
         cursor = db._conn.execute("SELECT version FROM schema_version")
         version = cursor.fetchone()[0]
-        assert version == 6
+        assert version == 7
 
     def test_title_column_exists(self, db):
         """Verify the title column was created in the sessions table."""
@@ -996,13 +1017,19 @@ class TestSchemaInit:
 
         # Verify migration
         cursor = migrated_db._conn.execute("SELECT version FROM schema_version")
-        assert cursor.fetchone()[0] == 6
+        assert cursor.fetchone()[0] == 7
 
         # Verify title column exists and is NULL for existing sessions
         session = migrated_db.get_session("existing")
         assert session is not None
         assert session["title"] is None
 
+        # Verify api_call_count column was added with default 0
+        cursor = migrated_db._conn.execute(
+            "SELECT api_call_count FROM sessions WHERE id = 'existing'"
+        )
+        assert cursor.fetchone()[0] == 0
+
         # Verify we can set title on migrated session
         assert migrated_db.set_session_title("existing", "Migrated Title") is True
         session = migrated_db.get_session("existing")