feat: GUI /memory page + disk/date_math/sleep_timer packs (10 new commands)

GUI: Memory management completes the management trio (/macros + /scheduler + /memory).

Tauri commands (crates/jarvis-gui/src/tauri_commands/memory.rs)
  - memory_list             → Vec<MemoryFact{key, value, created_at, last_used_at, use_count}>
  - memory_remember(k, v)   → persist new fact (or overwrite)
  - memory_forget(key)      → delete by exact key
  - memory_search(q, limit) → substring search

GUI /memory page (frontend/src/routes/memory/index.svelte)
  - Top: add-fact form (key + value inputs + "+Добавить" button)
  - Substring filter input for the list
  - Per-card: key + use_count badge + value (highlighted box) + timestamps +
    "Забыть" button with confirm() guard
  - Auto-sorted by recency (last_used_at desc)
  - Empty state shows voice-hint: 'скажи Jarvis-у "запомни что я люблю чай улун"'

Header (frontend/src/components/Header.svelte)
  - New "Память" button between /scheduler and /settings.
  - i18n: header-memory in ru/en/ua FTL files.

New voice packs

resources/commands/disk/ (2 cmds)
  - disk.free      "сколько свободно на диске" / "сколько места на диске C"
                   PowerShell Get-PSDrive → speaks "Свободно X ГБ из Y, это N%"
  - disk.list      "какие у меня диски" → "C 120 ГБ, D 300 ГБ, E 50 ГБ"

resources/commands/date_math/ (2 cmds)
  - date.days_until    "сколько дней до нового года" / "сколько до 8 марта" /
                       "сколько до 15 марта" — recognises Russian months,
                       holidays (Новый год, Рождество, 8 марта, 9 мая).
                       Auto-rolls to next year if target already passed.
                       Russian-grammar pluralisation (день/дня/дней).
  - date.day_of_week   "какой сегодня день недели" — Zeller's congruence,
                       maps to ru day name.

resources/commands/sleep_timer/ (3 cmds)
  - sleep_timer.pause_in    "выключи музыку через 30 минут"
                            → scheduler one-shot lua action that fires media
                            VK_MEDIA_PLAY_PAUSE via the existing media_keys helper.
                            (Auto-generates _fire_pause.lua wrapper if missing.)
  - sleep_timer.shutdown_in "выключи компьютер через 1 час"
                            → shutdown.exe /s /t <secs>. Caps at 24 hours.
                            Speaks "Скажите 'отмени таймер' чтобы передумать."
  - sleep_timer.cancel      "отмени таймер выключения" / "не выключай компьютер"
                            → shutdown /a + scheduler.remove("sleep_timer_pause"),
                            idempotent.

Pack count: 64 → 67. Tests: 112/112 pass.
Build: cargo build --release -p jarvis-gui green.

resources/commands/date_math/days_until.lua

@@ -0,0 +1,74 @@
+-- "Сколько дней до нового года" / "сколько до 15 марта"
+local phrase = (jarvis.context.phrase or ""):lower()
+local t = jarvis.context.time
+local current_year = t.year
+
+local MONTHS = {
+    ["январ"]=1, ["феврал"]=2, ["март"]=3, ["апрел"]=4, ["май"]=5, ["мая"]=5, ["июн"]=6,
+    ["июл"]=7, ["август"]=8, ["сентябр"]=9, ["октябр"]=10, ["ноябр"]=11, ["декабр"]=12,
+}
+
+-- Special phrases
+local target_y, target_m, target_d
+
+if phrase:find("нов") and phrase:find("год") then
+    target_y, target_m, target_d = current_year + 1, 1, 1
+    if t.month == 1 and t.day == 1 then target_y = current_year end
+elseif phrase:find("рожд") then
+    target_y, target_m, target_d = current_year, 1, 7 -- ru orthodox
+elseif phrase:find("8 март") or phrase:find("восьмого март") then
+    target_y, target_m, target_d = current_year, 3, 8
+elseif phrase:find("9 ма") or phrase:find("девятое ма") then
+    target_y, target_m, target_d = current_year, 5, 9
+end
+
+-- Generic "до N <месяц>"
+if not target_y then
+    local d = tonumber(phrase:match("до%s+(%d+)"))
+    if d then
+        for stem, month in pairs(MONTHS) do
+            if phrase:find(stem) then
+                target_d, target_m, target_y = d, month, current_year
+                break
+            end
+        end
+    end
+end
+
+if not target_y then
+    return jarvis.cmd.error("Не понял дату.")
+end
+
+-- If target this year already passed, jump to next year
+local function days_since_epoch(y, m, d)
+    -- approximate: works for diffs within ~100 years
+    local total = y * 365 + math.floor(y / 4) - math.floor(y / 100) + math.floor(y / 400)
+    local cum = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }
+    total = total + cum[m] + (d - 1)
+    -- leap-day adjustment
+    local leap = (y % 4 == 0 and y % 100 ~= 0) or (y % 400 == 0)
+    if leap and m > 2 then total = total + 1 end
+    return total
+end
+
+local now = days_since_epoch(t.year, t.month, t.day)
+local target = days_since_epoch(target_y, target_m, target_d)
+
+if target < now then
+    target_y = target_y + 1
+    target = days_since_epoch(target_y, target_m, target_d)
+end
+
+local diff = target - now
+if diff == 0 then
+    return jarvis.cmd.ok("Сегодня.")
+end
+
+-- Russian grammar: 1 день, 2-4 дня, 5+ дней
+local last = diff % 10
+local unit = "дней"
+if last == 1 and diff % 100 ~= 11 then unit = "день"
+elseif last >= 2 and last <= 4 and (diff % 100 < 10 or diff % 100 >= 20) then unit = "дня"
+end
+
+return jarvis.cmd.ok(string.format("%d %s.", diff, unit))