feat: Wave 6 — focus mode, cooking timer, memory admin

Focus mode (`focus/`):
- focus.start ("режим фокуса" / "focus mode"): three side-effects in one
  voice trigger:
    1. switch profile to "work" (silences fun/banter)
    2. enable Windows Focus Assist via registry tweak (QuietHours key)
    3. schedule a stretch reminder in 50 minutes through the persistent
       scheduler — so it survives daemon restart
- focus.stop: undoes all three, including cancelling pending stretch
  reminders by matching their scheduler name. Best-effort: any one
  failing doesn't block the others.

Cooking timer (`cooking/`):
- Recognises 16+ dish names (чай, кофе, омлет, яйца, макароны, паста,
  рис, гречка, картошка, курица, пицца, etc.) and starts a preset-
  duration scheduler reminder ("Сэр, чай готов.").
- Single Lua script, table-driven — adding a recipe is one line.
- EN phrases for the same dishes ("boiling pasta", "frying eggs", ...).

Memory admin (`memory_admin/`):
- memory_admin.count → speak fact count with full RU pluralisation.
- memory_admin.list → speak 5 most-recent + toast the rest.
- memory_admin.wipe → ONLY fires on "точно забудь все" prefix (not bare
  "забудь все") so we can't disaster-wipe by accident.
- Adds `long_term_memory::clear_all() -> usize` returning removed count
  + Lua binding `jarvis.memory.clear_all()`.
- One extra unit test for `clear_all`.

Tests: 139 → 140 (+1). Pack count: 92 → 95.

resources/commands/focus/start.lua

@@ -0,0 +1,65 @@
+-- Enter focus mode — three side-effects bundled into one voice trigger:
+--   1. activate "work" profile (silences fun/games/banter commands)
+--   2. enable Windows Focus Assist (Quiet Hours) via registry tweak
+--   3. schedule a "стретчинг" reminder in 50 minutes via the persistent scheduler
+--
+-- All three are independent — if one fails, the rest still happen.
+
+local lang = jarvis.context.language
+
+local report = {}
+
+-- 1) Profile switch (best effort)
+local ok1, err1 = pcall(function() jarvis.profile.set("work") end)
+if ok1 then
+    table.insert(report, lang == "ru" and "профиль 'работа'" or "work profile")
+else
+    jarvis.log("warn", "focus.start: profile.set failed: " .. tostring(err1))
+end
+
+-- 2) Windows Focus Assist: writes the registry key Windows uses for
+--    "Priority only" mode. This is the same key Windows 11 toggles when you
+--    flip Focus on/off via the Action Center.
+local ps = [[
+$key = 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Notifications\Settings\Windows.SystemToast.QuietHours'
+if (-not (Test-Path $key)) { New-Item -Path $key -Force | Out-Null }
+Set-ItemProperty -Path $key -Name 'NOC_GLOBAL_SETTING_TOASTS_ENABLED' -Value 0 -Type DWord
+Write-Output 'fa-on'
+]]
+local cmd = 'powershell -NoProfile -ExecutionPolicy Bypass -Command "& {'
+    .. ps:gsub('\r?\n', '; '):gsub('"', '\\"')
+    .. '}"'
+local res = jarvis.system.exec(cmd)
+if res.success and (res.stdout or ""):find("fa%-on") then
+    table.insert(report, lang == "ru" and "уведомления выключены" or "notifications muted")
+else
+    jarvis.log("warn", "focus.start: focus assist registry tweak failed")
+end
+
+-- 3) Stretch reminder in 50 minutes (the canonical Pomodoro-XL value)
+local stretch_text = lang == "ru"
+    and "Сэр, 50 минут истекли. Встаньте, разомнитесь, посмотрите вдаль."
+    or  "Sir, 50 minutes are up. Stand, stretch, look away from the screen."
+
+local ok3, err3 = pcall(function()
+    jarvis.scheduler.add({
+        name     = lang == "ru" and "Стретч-пауза" or "Stretch break",
+        schedule = "in 50 minutes",
+        action   = { type = "speak", text = stretch_text },
+    })
+end)
+if ok3 then
+    table.insert(report, lang == "ru" and "пауза через 50 мин" or "break in 50 min")
+else
+    jarvis.log("warn", "focus.start: scheduler.add failed: " .. tostring(err3))
+end
+
+if #report == 0 then
+    return jarvis.cmd.error(lang == "ru" and "Ничего не получилось включить."
+                                          or "Couldn't enable anything.")
+end
+
+local summary = table.concat(report, ", ")
+return jarvis.cmd.ok(lang == "ru"
+    and ("Включил режим фокуса: " .. summary .. ". Удачной работы, сэр.")
+    or  ("Focus mode enabled: " .. summary .. ". Good luck, sir."))