chore(ui): remove dead AgentStripView fragment

AgentStripView was superseded by WorkConsole during the task-detail
redesign but never wired into any view and never deleted. Drops the
unused Border.agent-strip / diff-meter styles and the 14 agent.* locale
keys that only it referenced, and marks A4 in the feature-unification
spec as resolved by deletion.

src/ClaudeDo.Localization/locales/en.json

@@ -250,21 +250,7 @@
     }
   },
   "agent": {
-    "stopTip": "Stop agent",
-    "sendToQueue": "Send to queue",
-    "sendToQueueTip": "Queue this task for the worker to pick up",
-    "removeFromQueue": "Remove from queue",
-    "removeFromQueueTip": "Take this task back out of the queue",
-    "worktreeLabel": "WORKTREE",
-    "copyPathTip": "Copy path",
-    "diffLabel": "DIFF",
-    "openDiff": "Open diff",
-    "worktreeBtn": "Worktree",
-    "openWorktreeTip": "Open worktree in file explorer",
-    "continue": "Continue",
-    "continueTip": "Resume the last session and keep going",
-    "resetAndRetry": "Reset & retry",
-    "resetAndRetryTip": "Discard the worktree and re-queue the task to run from scratch"
+    "openWorktreeTip": "Open worktree in file explorer"
   },
   "notes": {
     "today": "Today",