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/en/lanes.json

@@ -49,7 +49,7 @@
   "addLaneToolClaude": "Claude Code",
   "addLaneToolCodex": "Codex",
   "addLaneToolHint": "Which CLI drives this lane. Cannot be changed later.",
-  "addLaneWriteDocsHint": "Opens the lane's terminal on creation and runs the /sg-all:sg-md-writing skill there.",
+  "addLaneWriteDocsHint": "On creation, opens the lane's terminal and runs /sg-all:sg-md-writing there: creates CLAUDE.md/AGENTS.md if missing, or updates them concisely if they already exist.",
   "addLaneWriteDocsLabel": "Create/update readme file",
   "autoStage": "auto: {{stage}}",
   "browse.button": "Browse",