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>

ui/src/components/AgentMissionControl.tsx

@@ -72,9 +72,13 @@ export function AgentMissionControl({
               ? `${agents.length} ${agents.length === 1 ? 'agent' : 'agents'} active`
               : orchestratorStatus?.state === 'initializing'
                 ? 'Initializing'
-                : orchestratorStatus?.state === 'complete'
-                  ? 'Complete'
-                  : 'Orchestrating'
+                : orchestratorStatus?.state === 'draining'
+                  ? 'Draining'
+                  : orchestratorStatus?.state === 'paused'
+                    ? 'Paused'
+                    : orchestratorStatus?.state === 'complete'
+                      ? 'Complete'
+                      : 'Orchestrating'
             }
           </Badge>
         </div>