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/pages/Workspace.tsx

@@ -41,6 +41,7 @@
  * ----------------------------------------------------------------------------- */
 
 import { useCallback, useEffect, useState, useSyncExternalStore } from "react";
+import { useSearchParams } from "react-router-dom";
 import { useTranslation } from "react-i18next";
 import { Plus, Square, Columns2, Grid2x2, Pencil } from "lucide-react";
 import { api } from "../lib/api";
@@ -198,6 +199,7 @@ function ConsoleArea({
 export function Workspace() {
   const { t: tLanes } = useTranslation("lanes");
   const wsConnected = useSyncExternalStore(eventBus.onConnection, () => eventBus.connected);
+  const [searchParams, setSearchParams] = useSearchParams();
 
   // Lane state
   const [lanes, setLanes] = useState<Lane[]>([]);
@@ -274,6 +276,26 @@ export function Workspace() {
     }
   }, []);
 
+  // Deep link from a notification click (`/workspace?lane=<id>`, see
+  // useNotifications' laneUrlForSession): once that lane is in the loaded
+  // list, select it and drop the param so a later manual lane switch sticks.
+  useEffect(() => {
+    const laneParam = searchParams.get("lane");
+    if (laneParam === null || lanes.length === 0) return;
+    const paramId = Number(laneParam);
+    if (lanes.some((l) => l.id === paramId)) {
+      setSelectedLaneId(paramId);
+    }
+    setSearchParams(
+      (prev) => {
+        const next = new URLSearchParams(prev);
+        next.delete("lane");
+        return next;
+      },
+      { replace: true }
+    );
+  }, [lanes, searchParams, setSearchParams]);
+
   useEffect(() => {
     Promise.all([api.run.binary("claude"), api.run.binary("codex")])
       .then(([claude, codex]) => setBinaryStatus({ claude, codex }))