feat(scheduler): IMBA-5 proactive scheduler — reminders, daily briefings, intervals

Background thread that wakes J.A.R.V.I.S. on a schedule to speak reminders.
Nothing else competes here on desktop — Алиса/Сири are reactive-only.

Core (crates/jarvis-core/src/scheduler.rs)
  - Schedule::{Daily{h,m}, Interval{secs}, Once{at}} with Schedule::parse for
    "daily HH:MM" / "at HH:MM" / "every N minutes|hours" / "in N minutes|hours".
    Russian units (час/часа/часов/минут/секунд) also accepted.
  - ScheduledTask {id, name, schedule, action, last_fired, enabled, created_at}.
    Action::Speak{text} | Action::Lua{script_path}.
  - JSON persistence at <APP_CONFIG_DIR>/schedule.json, atomic write-through.
  - add/remove/clear/list/find; mark_fired auto-deletes Once tasks.
  - start_background() spawns a 30-second tick thread (idempotent). Each tick
    calls due_tasks(), fires Action via tts::speak_default (after voices::play_reply
    "ahem" cue) or Lua engine.
  - 7 unit tests (all passing).

Lua API (crates/jarvis-core/src/lua/api/scheduler.rs)
  - jarvis.scheduler.add({name, schedule, action={type, text|script_path}})
  - jarvis.scheduler.{list, count, remove(id), clear}.
  - Tasks come back as {id, name, schedule_human, action, enabled, last_fired}.

Wire-up (crates/jarvis-app/src/main.rs)
  - scheduler::init() + scheduler::start_background() after profiles::init.
  - Tasks survive restarts via schedule.json.

Voice commands (resources/commands/scheduler/, 6 ids)
  - scheduler.add_reminder    "напомни через 5 минут выключить кофеварку"
  - scheduler.add_at          "напомни в 18:00 забрать ребёнка"
  - scheduler.add_recurring   "каждые 2 часа напоминай попить воды"
  - scheduler.add_daily       "каждый день в 9:00 делай briefing"
  - scheduler.list            "что у меня запланировано"
  - scheduler.clear           "очисти расписание"

Russian-aware parsers (час/часа/часов, минут/минуту/минуты) live inside the Lua
packs — easy to extend without touching Rust.

Tests: 31/31 jarvis-core unit tests pass (24 prior + 7 scheduler).
Build: cargo build --release -p jarvis-app and -p jarvis-gui both green.

resources/commands/scheduler/add_at.lua

@@ -0,0 +1,58 @@
+-- "напомни в 18:00 забрать ребёнка"
+local phrase = (jarvis.context.phrase or ""):lower()
+
+local body = jarvis.text.strip_trigger(phrase, {
+    "напомни сегодня в",
+    "напомни в",
+    "разбуди в",
+    "поставь напоминалку на",
+    "remind me at",
+    "wake me at",
+    "нагадай о",
+    "розбуди о",
+})
+
+body = body:gsub("^[%s,:%.]+", ""):gsub("%s+$", "")
+
+-- Parse "HH:MM <text>" or "HH MM <text>"
+local h, m, rest = body:match("^(%d%d?)%s*[:%-%s]%s*(%d%d?)%s*(.*)$")
+if not h then
+    h, rest = body:match("^(%d%d?)%s*(.*)$")
+    if not h then
+        jarvis.speak("Не понял время.")
+        jarvis.audio.play_error()
+        return { chain = false }
+    end
+    m = "00"
+end
+m = m or "00"
+
+local hn = tonumber(h)
+local mn = tonumber(m)
+if hn < 0 or hn > 23 or mn < 0 or mn > 59 then
+    jarvis.speak("Время вне диапазона.")
+    jarvis.audio.play_error()
+    return { chain = false }
+end
+
+local schedule = string.format("at %02d:%02d", hn, mn)
+local text_body = (rest or ""):gsub("^[%s,:%.]+", ""):gsub("%s+$", "")
+if text_body == "" then text_body = "Напоминание." end
+
+local ok, err = pcall(function()
+    jarvis.scheduler.add({
+        name = "Reminder",
+        schedule = schedule,
+        action = { type = "speak", text = text_body }
+    })
+end)
+if not ok then
+    jarvis.log("warn", "scheduler.add: " .. tostring(err))
+    jarvis.speak("Не получилось.")
+    jarvis.audio.play_error()
+    return { chain = false }
+end
+
+jarvis.speak(string.format("Напомню в %02d:%02d.", hn, mn))
+jarvis.audio.play_ok()
+return { chain = false }