[updater] macOS: updated .app installed with 0700 permissions (tempfile TempDir mode), unlaunchable for other users

### Describe the bug

On macOS, an app updated through `tauri-plugin-updater` ends up installed with **`0700` permissions on the `.app` bundle root**. On multi-user Macs, every user other than the one who ran the update gets "You do not have permission to open the application" when launching it from `/Applications`.

### Mechanism

In [`plugins/updater/src/updater.rs`](https://github.com/tauri-apps/plugins-workspace/blob/v2/plugins/updater/src/updater.rs), macOS `install_inner`:

1. The update is extracted into a `tempfile::TempDir` ([L1228-L1230](https://github.com/tauri-apps/plugins-workspace/blob/v2/plugins/updater/src/updater.rs#L1228-L1230)). `tempfile` creates temp directories with mode `0700` by design.
2. The archive entries are unpacked with the first path component stripped ([L1238](https://github.com/tauri-apps/plugins-workspace/blob/v2/plugins/updater/src/updater.rs#L1238)), so the TempDir itself becomes the new bundle root.
3. That directory is renamed into place as the installed `.app` ([L1302](https://github.com/tauri-apps/plugins-workspace/blob/v2/plugins/updater/src/updater.rs#L1302)). `rename` preserves the mode, so the installed bundle root is `drwx------`.

The tar entries inside keep their archived modes; it's specifically the bundle root directory (former TempDir) that ends up `0700`. Nothing chmods it afterwards.

### Reproduction

On any Mac with two user accounts:

1. As user A, install an app whose updates ship via this plugin (fresh install from DMG: bundle root is `drwxr-xr-x`).
2. Let the app auto-update.
3. `stat -f '%Sp %Su' /Applications/MyApp.app` → `drwx------ userA`.
4. As user B, try to launch the app → permission error (user B can't even traverse into the bundle).

### Suggested fix

After the final rename (or on the extract dir before the rename), set the bundle root to `0755`:

```rust
std::fs::set_permissions(&self.extract_path, std::fs::Permissions::from_mode(0o755))?;
```

Alternatively, extract into a *child* directory of the TempDir so the archived `.app` directory (with its own archived mode) is what gets renamed into place, rather than the TempDir itself.

Happy to open a PR either way.

### Platform and versions

- plugin: `tauri-plugin-updater` 2.10.0 (code unchanged at current `v2` HEAD)
- macOS (any); analysis done on macOS 27.0, tauri 2.11.2

Read plugins/updater/src/updater.rs, especially the macOS install_inner flow at the extraction and final-rename locations around lines 1228-1238 and 1302. Reproduce the update on macOS and inspect the installed bundle with stat; done means the .app root is traversable by other users and they can launch it from /Applications.

Written by the indexing model from the issue text.