fix(security): harden auth system and fix run journal logic bug (#2593)

* fix(security): harden auth system and fix run journal logic bug

  - Fix inverted condition in RunJournal.on_chat_model_start that prevented
    first human message capture (not messages → messages)
  - Pre-hash passwords with SHA-256 before bcrypt to avoid silent 72-byte
    truncation vulnerability
  - Move load_dotenv() from module scope into get_auth_config() to prevent
    import-time os.environ mutation breaking test isolation
  - Return generic ‘Invalid token’ instead of exposing specific error
    variants (expired, malformed, invalid_signature) to clients
  - Make @require_auth independently enforce 401 instead of silently
    passing through when AuthMiddleware is absent
  - Rate-limit /setup-status endpoint with per-IP cooldown to mitigate
    initialization-state information leak
  - Document in-process rate limiter limitation for multi-worker deployments

* fix(security): return 429+Retry-After on setup-status rate limit, bound cooldown dict

Agent-Logs-Url: https://github.com/bytedance/deer-flow/sessions/070d0be8-99a5-46c8-85bb-6b81b5284021

Co-authored-by: WillemJiang <219644+WillemJiang@users.noreply.github.com>

* fix(security): add versioned password hashes with auto-migration on login

  The SHA-256 pre-hash change silently broke verification for any existing
  bcrypt-only password hashes. Introduce a <N>$ prefix scheme so hashes
  are self-describing:

  - v2 (current): bcrypt(b64(sha256(password))) with $ prefix
  - v1 (legacy): plain bcrypt, prefixed $ or bare (no prefix)

  verify_password auto-detects the version and falls back to v1 for older
  hashes. LocalAuthProvider.authenticate() now rehashes legacy hashes to v2
  on successful login via needs_rehash(), so existing users upgrade
  transparently without a dedicated migration step.

* fix(auth): harden verify_password, best-effort rehash, update require_auth docstring, downgrade journal logging

- password.py: wrap bcrypt.checkpw in try/except → return False for malformed/corrupt hashes instead of crashing
- local_provider.py: wrap auto-rehash update_user() in try/except so transient DB errors don't fail valid logins
- authz.py: update require_auth docstring to reflect independent 401 enforcement
- journal.py: downgrade on_chat_model_start from INFO to DEBUG, log only metadata (batch_count, message_counts) instead of full serialized/messages content

Agent-Logs-Url: https://github.com/bytedance/deer-flow/sessions/48c5cf31-a4ab-418a-982a-6343c37bb299

Co-authored-by: WillemJiang <219644+WillemJiang@users.noreply.github.com>

* fix(auth): address code review - narrow ValueError catch, add rehash warning log, rename num_batches

Agent-Logs-Url: https://github.com/bytedance/deer-flow/sessions/48c5cf31-a4ab-418a-982a-6343c37bb299

Co-authored-by: WillemJiang <219644+WillemJiang@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

backend/packages/harness/deerflow/runtime/journal.py

@@ -138,10 +138,16 @@ class RunJournal(BaseCallbackHandler):
         # Mark this run_id as seen so on_llm_end knows not to increment again.
         self._cached_prompts[rid] = []
 
-        logger.info(f"on_chat_model_start {run_id}: tags={tags} serialized={serialized} messages={messages}")
+        logger.debug(
+            "on_chat_model_start %s: tags=%s num_batches=%d message_counts=%s",
+            run_id,
+            tags,
+            len(messages),
+            [len(batch) for batch in messages],
+        )
 
         # Capture the first human message sent to any LLM in this run.
-        if not self._first_human_msg and not messages:
+        if not self._first_human_msg and messages:
             for batch in messages.reversed():
                 for m in batch.reversed():
                     if isinstance(m, HumanMessage) and m.name != "summary":