chore(agent-office): drop unused break state styling

Backend no longer emits the 'break' state (see web-backend
de8adae). Remove the matching entry from STATE_COLORS and the
.ao-card-dot.break CSS rule. Safe because AgentCard's unknown-state
fallback (DEFAULT_STATE_COLOR) handles any stray legacy value.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/pages/agent-office/AgentOffice.css

@@ -97,7 +97,6 @@
 .ao-card-dot.working          { background: #22c55e; }
 .ao-card-dot.error            { background: #ef4444; }
 .ao-card-dot.waiting_approval { background: #f59e0b; }
-.ao-card-dot.break            { background: #94a3b8; }
 .ao-card-dot.pulse {
   animation: ao-pulse 1.6s ease-in-out infinite;
 }

src/pages/agent-office/constants.js

@@ -38,7 +38,6 @@ export const STATE_COLORS = {
   working:          { color: '#22c55e', pulse: true  },
   error:            { color: '#ef4444', pulse: false },
   waiting_approval: { color: '#f59e0b', pulse: true  },
-  break:            { color: '#94a3b8', pulse: false },
 };
 
 export const DEFAULT_STATE_COLOR = STATE_COLORS.idle;