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).

README.md

@@ -242,9 +242,9 @@ also **advances the declared stage** — the one place an inference moves the bl
 `current` ring, because a Codex session has no hook and nothing else would ever
 move it. What a Codex lane cannot get for free is *evidence*: an auto-advanced
 node stays amber (`passed-no-evidence`), never green, since only the session
-itself can say what it finished. Three things help it get there: the run console
-pre-fills a codex pane's opening prompt with a stage-declaration checklist built
-from its own pipeline nodes, `agenthub lanes agents install` writes the same
+itself can say what it finished. Two things help it get there (the run console
+no longer pre-fills anything into the prompt box — that box is the user's to
+type): `agenthub lanes agents install` writes the stage-declaration
 instructions as a marker-delimited block in the lane's `AGENTS.md`, and a 60s
 sweep (`DASHBOARD_CODEX_NUDGE_MS`, `0` disables) types a one-line reminder into
 a lane's pane if its current stage sits without evidence for more than two