Expose the shell's remaining UI-only toggles over IPC

Every toggle you could only reach by mouse or panel hotkey is now
scriptable through omarchy-shell:

- omarchy.bluetooth toggleBluetooth — the radio (was right-click / B)
- omarchy.network toggleNetwork — Wi-Fi on/off (was W in the panel)
- omarchy.tailscale toggleTailscale — the connection as one call,
  matching the widget's right-click, instead of separate up/down
- omarchy.clock toggleWeekStart — calendar week start (was W)
- shell toggleBarTransparency — the bar background (was manage UI only)

Bluetooth and network follow the power/monitor pattern: manageIpc: false
so the panel owns the target's single IpcHandler and can extend it past
the inherited lifecycle methods.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/omarchy-shell.md

@@ -100,6 +100,7 @@ individual plugins (`bar`, `image-selector`, …).
 | `call <id> <method> <arg>`            | call an already-loaded plugin   |
 | `rescanPlugins`                       | re-walk plugin dirs and hot-reload plugin code |
 | `reloadConfig`                        | reload shell.json               |
+| `toggleBarTransparency`               | flip the bar background between solid and transparent |
 | `setPluginEnabled <id> <"true"\|…>`   | flip enabled bit (`ok` / `unknown`) |
 | `enablePlugin <id> <placementJson>`   | enable and place in one mutation |
 | `moveBarWidget <id> <placementJson>`  | move a configured widget        |