fix: handle pausing/draining states in UI guards and process cleanup

Follow-up fixes after merging PR #183 (graceful pause/drain mode):

- process_manager: _stream_output finally block now transitions from
  pausing/paused_graceful to crashed/stopped (not just running), and
  cleans up the drain signal file on process exit
- App.tsx: block Reset button and R shortcut during pausing/paused_graceful
- AgentThought/ProgressDashboard: keep thought bubble visible while pausing
- OrchestratorAvatar: add draining/paused cases to animation, glow, and
  description switch statements
- AgentMissionControl: show Draining/Paused badge text for new states
- registry.py: remove redundant type annotation to fix mypy no-redef
- process_manager.py: add type:ignore for SQLAlchemy Column assignment
- websocket.py: reclassify test-pass lines as 'testing' not 'success'
- review-pr.md: add post-review recommended action guidance

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

registry.py

@@ -743,7 +743,7 @@ def get_effective_sdk_env() -> dict[str, str]:
                 sdk_env[var] = value
         return sdk_env
 
-    sdk_env: dict[str, str] = {}
+    sdk_env = {}
 
     # Explicitly clear credentials that could leak from the server process env.
     # For providers using ANTHROPIC_AUTH_TOKEN (GLM, Custom), clear ANTHROPIC_API_KEY.