feat(run,notifications,profiles): stop sending prompts nobody typed, and fix notification + profile delivery

Run console:
- Picking a pipeline no longer pre-writes anything into the prompt box
  (`promptPrefill` in `LaneConsolePane.tsx` is gone — it wrote the driving
  slash command on a claude lane and a stage checklist on a codex one).
  Whatever sits in that box is sent as a real prompt the moment the run
  starts, so the box is the user's alone now.
- Resuming a session sends NO prompt at all (`handleStart` in `RunSetup.tsx`):
  the resumed session carries its own transcript, and leftover text in the box
  fired an extra turn into it.

Notifications:
- `client/src/lib/notify.ts` is now the ONE sender, used by both
  `useNotifications` and Settings' test button, and it reports where the
  notification landed: `POST /api/push/send` answering `{native:false,pushed:0}`
  means it went NOWHERE, so the client falls back to a local notification
  instead of counting the 200 as delivered.
- A notification carries the lane that raised it (`/workspace?lane=<id>`), and
  Workspace selects that lane on arrival.

Profiles:
- `server/lib/cc-profiles.js` reads and writes the macOS login Keychain item
  `Claude Code-credentials`, where the `claude` CLI actually keeps
  `claudeAiOauth` on darwin — a switch used to rewrite a file nothing reads.
  The file stays the fallback, is kept in step only when it already exists, and
  `AGENTHUB_CC_KEYCHAIN=0` pins it (tests set it).

Tests: npm run test:server (1820 pass), client vitest (553 pass).

client/src/i18n/locales/vi/settings.json

@@ -84,7 +84,11 @@
     "sessionComplete": "Phiên hoàn tất",
     "sessionError": "Phiên gặp lỗi",
     "subagentSpawned": "Subagent được tạo",
+    "testBlocked": "Trình duyệt chưa cấp quyền thông báo.",
     "testBody": "Thông báo đang hoạt động!",
+    "testFailed": "Không hiển thị được thông báo nào.",
+    "testLocal": "Trình duyệt chưa đăng ký push nên thông báo được hiện tại chỗ. Web Push cần origin bảo mật (localhost hoặc HTTPS) và service worker đã đăng ký.",
+    "testSent": "Đã gửi qua push — kiểm tra trung tâm thông báo.",
     "testTitle": "Agent Monitor",
     "title": "Thông báo",
     "turnComplete": "Claude trả lời xong"