feat: add smart respawn integration and priority todos (Phase 2)

Smart Respawn Integration (2.5):
- Check circuit breaker OPEN state before respawn (blocks cycle)
- Check RALPH_STATUS EXIT_SIGNAL=true to stop respawn
- Check STATUS=BLOCKED to pause respawn for human intervention
- Use RECOMMENDATION from RALPH_STATUS in update prompt
- Emit respawn:blocked SSE event with reason and details
- Show notification when respawn is blocked
- Visual blocked state with pulsing red indicator

Priority-based Todos (part of 2.3):
- Add RalphTodoPriority type (P0/P1/P2/null)
- Parse priority from todo content (P0:, Critical:, High Priority, etc.)
- Add priority field to RalphTodoItem interface
- Update frontend to display priority badges with colors
- Sort todos by priority (P0 > P1 > P2) then by status
- Add CSS for priority badges and highlighted cards

Bump version to 0.1391

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/types.ts

@@ -718,6 +718,12 @@ export interface RalphTrackerState {
   elapsedHours: number | null;
 }
 
+/**
+ * Priority levels for todo items.
+ * Matches @fix_plan.md format (P0=critical, P1=high, P2=normal).
+ */
+export type RalphTodoPriority = 'P0' | 'P1' | 'P2' | null;
+
 /**
  * A detected todo item from Claude Code output
  */
@@ -730,6 +736,8 @@ export interface RalphTodoItem {
   status: RalphTodoStatus;
   /** Timestamp when detected */
   detectedAt: number;
+  /** Priority level (P0=critical, P1=high, P2=normal) */
+  priority: RalphTodoPriority;
 }
 
 /**
@@ -878,14 +886,6 @@ export function createInitialCircuitBreakerStatus(): CircuitBreakerStatus {
   };
 }
 
-// ========== Priority Todo Types ==========
-
-/**
- * Priority levels for todo items.
- * Matches @fix_plan.md format.
- */
-export type RalphTodoPriority = 'P0' | 'P1' | 'P2' | null;
-
 /**
  * Creates initial Ralph tracker state
  * @returns Fresh Ralph tracker state with defaults