feat(commands): add PC control packs — volume, apps, file_search, output_device

All four packs are pure Lua (sandbox=full) and call out to PowerShell helpers
where COM / native APIs are needed. No new Rust code, no rebuild required:
post_build.py --sync copies them under target/{debug,release}/resources/.

volume/
  - volume_up / volume_down: 5x VK_VOLUME_UP|DOWN via keybd_event
  - volume_mute: VK_VOLUME_MUTE
  - volume_max: 50x VK_VOLUME_UP (system clamps)
  Helper _volume_helper.ps1 P/Invokes user32!keybd_event.

apps/
  - open_browser  : start "" https://www.google.com (uses system default browser)
  - open_notepad  : notepad.exe
  - open_calculator: calc.exe
  - open_explorer : explorer.exe
  - open_terminal : wt.exe, falls back to powershell.exe
  - open_settings : ms-settings: protocol
  - open_task_manager: taskmgr.exe
  - lock_screen   : rundll32 user32.dll,LockWorkStation
  - screenshot    : System.Drawing capture to ~/Pictures/jarvis_screenshot_*.png

file_search/
  - find file <query> : recursive Get-ChildItem in Desktop/Documents/Downloads
    (depth 3, top 5 matches). Strips Russian/English/Ukrainian trigger
    prefixes from the recognized phrase, then opens explorer /select on the
    first hit and notifies with the total count.

output_device/
  - list_output_devices : enumerates active render endpoints via
    IMMDeviceEnumerator and notifies friendly names with indices
  - next_output_device  : cycles the system default render device via the
    undocumented IPolicyConfig::SetDefaultEndpoint (eConsole/Multimedia/
    Communications). Tested locally — listed 7 devices, current correctly
    identified at index 5.

resources/commands/volume/command.toml

@@ -0,0 +1,106 @@
+[[commands]]
+id = "volume_up"
+type = "lua"
+script = "volume_up.lua"
+sandbox = "full"
+timeout = 3000
+
+[commands.phrases]
+ru = [
+    "громче",
+    "сделай громче",
+    "прибавь звук",
+    "увеличь громкость",
+    "погромче",
+]
+en = [
+    "louder",
+    "volume up",
+    "increase volume",
+    "turn it up",
+]
+ua = [
+    "голосніше",
+    "зроби голосніше",
+    "збільш гучність",
+]
+
+
+[[commands]]
+id = "volume_down"
+type = "lua"
+script = "volume_down.lua"
+sandbox = "full"
+timeout = 3000
+
+[commands.phrases]
+ru = [
+    "тише",
+    "сделай тише",
+    "убавь звук",
+    "уменьши громкость",
+    "потише",
+]
+en = [
+    "quieter",
+    "volume down",
+    "decrease volume",
+    "turn it down",
+]
+ua = [
+    "тихіше",
+    "зроби тихіше",
+    "зменш гучність",
+]
+
+
+[[commands]]
+id = "volume_mute"
+type = "lua"
+script = "volume_mute.lua"
+sandbox = "full"
+timeout = 3000
+
+[commands.phrases]
+ru = [
+    "выключи звук",
+    "заткнись",
+    "тишина",
+    "приглуши звук",
+    "отключи звук",
+]
+en = [
+    "mute",
+    "silence",
+    "shut up",
+    "be quiet",
+]
+ua = [
+    "вимкни звук",
+    "тиша",
+    "стихни",
+]
+
+
+[[commands]]
+id = "volume_max"
+type = "lua"
+script = "volume_max.lua"
+sandbox = "full"
+timeout = 3000
+
+[commands.phrases]
+ru = [
+    "максимальная громкость",
+    "звук на максимум",
+    "на полную",
+]
+en = [
+    "max volume",
+    "full volume",
+    "maximum",
+]
+ua = [
+    "максимальна гучність",
+    "звук на максимум",
+]