feat(commands): tier-1 — translate, math, theme toggle, project opener, sound panel

Five more portable Lua command packs. Bumps the total from 16 to 21
packs. cargo test -p jarvis-core --lib commands::tests still 3/3.

translate/ — translate.lua. Picks the target language from triggers
like "переведи на английский" / "translate to russian"; falls back to
English when only "переведи X" is heard. Sends to Groq with a strict
"translation only" system prompt at temp 0.3. Drops the result into
the clipboard, fires a notify, and speaks via PowerShell SAPI in the
matching ISO voice (ru-RU / uk-UA / en-US / de-DE etc.) so a German
translation actually sounds German.

math/ — math.lua. Strips the trigger ("посчитай" / "calculate" /
"сколько будет" / "what is" / ...), sends the remainder to Groq with
temp=0.0 and max_tokens=64, asking ONLY for the numeric result. If
the model replies "нет" (the system-prompt sentinel for non-math),
plays not_found instead of speaking nonsense. Otherwise speaks
"Получилось X" via SAPI.

theme/ — set.lua dispatched by command_id (theme_dark / theme_light).
Flips AppsUseLightTheme + SystemUsesLightTheme under
HKCU\...\Themes\Personalize via Set-ItemProperty. No reboot needed,
Windows shell re-themes immediately.

projects/ — open.lua + list.lua. Reads/creates
%USERPROFILE%\Documents\jarvis-projects.json (a flat
[{"name": ..., "path": ...}] list). open.lua strips the trigger,
exact-matches then substring-matches the project name, opens the path
in VS Code if `code.cmd` is on PATH, otherwise in Explorer. First
call creates a sample config with jarvis-rust / jarvis-python /
dietpi entries pointing under USERPROFILE so it works on any machine.
list.lua just notifies the configured project names.

sound_panel/ — open.lua. Two-liner: rundll32 mmsys.cpl,,1 (Recording
tab). Useful both as a standalone "открой настройки звука" and as
the place to fix the mic-disabled state that prevents jarvis-app
from starting.

Portability: USERPROFILE / SystemDrive / PATH lookup throughout.

resources/commands/projects/command.toml

@@ -0,0 +1,36 @@
+[[commands]]
+id = "open_project"
+type = "lua"
+script = "open.lua"
+sandbox = "full"
+timeout = 5000
+
+[commands.phrases]
+ru = [
+    "открой проект",
+    "запусти проект",
+    "проект",
+    "открой папку проекта",
+]
+en = [
+    "open project",
+    "launch project",
+    "project",
+]
+ua = [
+    "відкрий проект",
+    "запусти проект",
+]
+
+
+[[commands]]
+id = "list_projects"
+type = "lua"
+script = "list.lua"
+sandbox = "full"
+timeout = 5000
+
+[commands.phrases]
+ru = ["какие у меня проекты", "список проектов", "покажи проекты"]
+en = ["list projects", "show projects"]
+ua = ["які в мене проекти", "перелік проектів"]