refactor(agent-office): drop the random idle→break→idle cycle

The pixel-office game UI is gone, so simulating coffee-break /
nap / walk states no longer serves any purpose. Remove:
- scheduler's _check_idle_breaks job (no more 60s idle scan)
- BaseAgent.check_idle_break() and _break_until field
- 'break' from VALID_STATES and from transition() branches
- IDLE_BREAK_THRESHOLD / BREAK_DURATION_MIN / BREAK_DURATION_MAX
  config knobs
- 'idle/break' guard in each agent's on_schedule (now just 'idle')

Agents now sit in 'idle' between scheduled jobs and explicit
commands. Display reads 'Idle' instead of churning between idle
and break.

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

agent-office/app/agents/base.py

@@ -1,12 +1,9 @@
-import asyncio
-import random
 import time
 from typing import Optional
 
-from ..config import IDLE_BREAK_THRESHOLD, BREAK_DURATION_MIN, BREAK_DURATION_MAX
 from ..db import add_log
 
-VALID_STATES = ("idle", "working", "waiting", "reporting", "break")
+VALID_STATES = ("idle", "working", "waiting", "reporting")
 
 class BaseAgent:
     agent_id: str = ""
@@ -14,7 +11,6 @@ class BaseAgent:
     state: str = "idle"
     state_detail: str = ""
     _idle_since: float = 0.0
-    _break_until: float = 0.0
     _ws_manager = None
 
     def __init__(self):
@@ -32,9 +28,6 @@ class BaseAgent:
 
         if new_state == "idle":
             self._idle_since = time.time()
-        elif new_state == "break":
-            duration = random.randint(BREAK_DURATION_MIN, BREAK_DURATION_MAX)
-            self._break_until = time.time() + duration
 
         add_log(self.agent_id, f"State: {old} -> {new_state} ({detail})")
 
@@ -48,19 +41,6 @@ class BaseAgent:
                 await self._ws_manager.send_notification(
                     self.agent_id, "task_completed", task_id, detail or "작업 완료"
                 )
-            if new_state == "break":
-                await self._ws_manager.send_agent_move(self.agent_id, "break_room")
-            elif old == "break" and new_state == "idle":
-                await self._ws_manager.send_agent_move(self.agent_id, "desk")
-
-    async def check_idle_break(self) -> None:
-        now = time.time()
-        if self.state == "idle" and (now - self._idle_since) > IDLE_BREAK_THRESHOLD:
-            if random.random() < 0.5:
-                break_type = random.choice(["커피 타임", "잠깐 산책", "졸고 있음"])
-                await self.transition("break", break_type)
-        elif self.state == "break" and now > self._break_until:
-            await self.transition("idle", "휴식 완료")
 
     async def on_schedule(self) -> None:
         raise NotImplementedError