fix: default the auth bridge on, and make the browser-view flag durable

A CLI running `claude login` inside the container binds a random ephemeral
loopback port and hands the provider a redirect pointing at it. The browser
is on the host, so the callback lands on a closed host port and the login
hangs with no diagnostic. The auth bridge is the thing that fixes this --
it mirrors container loopback listeners onto the same host port -- so
having it default to off made a hang the out-of-the-box experience.

`auth_bridge_enabled` now defaults to true through a
`default_auth_bridge_enabled()` serde helper, matching the shape already
used by `use_shared_auth_token`. Because the default is applied at
deserialisation, projects stored before the bridge existed pick it up too;
`migrate_from_value` writes neither flag, so nothing defeats it, and a
regression test pins that.

Separately, `BrowserViewManager.enabled` was in-memory only and the durable
`browser_view_enabled` field on the project record was never implemented.
Rather than sync the two, the cache is removed and the record becomes the
single home for the flag, mirroring how `AuthBridgeManager` already works.
`stop()` deliberately does not clear it, since container teardown and
migration reach that path and neither is the user changing their mind.
Durable does not mean auto-started: a restarted app reports enabled with
the viewer off.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

app/src-tauri/src/commands/project_commands.rs

@@ -1100,6 +1100,15 @@ pub async fn update_project(
 
     project.container_id = stored.container_id;
     project.status = stored.status;
+    // `browser_view_enabled` is owned by `set_browser_view_enabled` and is
+    // restored here rather than taken from the payload, exactly like
+    // `container_id` and `status` above. The Config tab has no control for it
+    // — the Browser tab's toggle is the only way it ever changes — so the
+    // project object the frontend round-trips carries whatever it was told at
+    // load time and would silently undo a toggle made since. `auth_bridge_enabled`
+    // is different and does arrive through this save: the Config tab edits it,
+    // which is why the reconcile below follows whatever was just persisted.
+    project.browser_view_enabled = stored.browser_view_enabled;
     project.created_at = stored.created_at;
     project.updated_at = chrono::Utc::now().to_rfc3339();