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).

server/lib/push.js

@@ -82,8 +82,12 @@ function showNativeNotificationIfElectron(title, body) {
  *
  * Returns `{ native, pushed, failed }` so the caller can surface what actually
  * happened in its API response — silent failures stop looking like success.
+ *
+ * @param {string} [url] Same-origin path (e.g. `/workspace?lane=3`) the
+ *   service worker's `notificationclick` handler navigates to. Undefined for
+ *   notifications with no specific target.
  */
-async function sendPushToAll(db, title, body) {
+async function sendPushToAll(db, title, body, url) {
   const native = showNativeNotificationIfElectron(title, body);
 
   const subscriptions = db.prepare("SELECT * FROM push_subscriptions").all();
@@ -102,6 +106,10 @@ async function sendPushToAll(db, title, body) {
     badge: "/favicon.svg",
     silent: false,
     sound: "default",
+    // `data` is the standard NotificationOptions field notificationclick reads
+    // back via `event.notification.data`; omitted entirely when there's no url
+    // so `event.notification.data` stays undefined rather than `{url: undefined}`.
+    ...(url ? { data: { url } } : {}),
   });
   const results = await Promise.allSettled(
     subscriptions.map((sub) =>