feat: implement Hermes session manager with SQLite + JSONL support (Phase 6)

- Add hermes.rs session provider with dual-source scanning:
  SQLite (state.db) as primary, JSONL transcripts as fallback
- Dynamic schema discovery via PRAGMA table_info for SQLite resilience
- Use read_head_tail_lines for efficient JSONL metadata extraction
  (head 30 lines for metadata, tail 10 for last_active_at)
- Support both flat and nested JSONL message formats
- Add SQLite session loading and transactional deletion
- Register hermes in parallel session scan (thread::scope)
- Add "hermes" to frontend ProviderFilter type
- 7 unit tests covering JSONL parsing, SQLite source parsing, deletion

src/components/sessions/SessionManagerPage.tsx

@@ -62,7 +62,8 @@ type ProviderFilter =
   | "claude"
   | "opencode"
   | "openclaw"
-  | "gemini";
+  | "gemini"
+  | "hermes";
 
 export function SessionManagerPage({ appId }: { appId: string }) {
   const { t } = useTranslation();