feat: Wave 10 — expense tracker pack (voice-driven)

resources/commands/expenses/ (4 commands):
- expenses.log     "потратил 500 на еду"     → append entry
- expenses.today   "сколько потратил сегодня" → today's total
- expenses.week    "сколько на неделе"       → 7-day rolling total
- expenses.breakdown "куда ушли деньги"      → top-5 categories

Storage: `jarvis.state` (auto-namespaced per-pack JSON). Wire format is
compact "ts1,amount1,cat1|ts2,amount2,cat2" so we don't need a JSON parser
inside Lua.

Phrase parsing:
- Trigger stripped via jarvis.text.strip_trigger.
- First number captured; "12,50" comma decimals accepted.
- Category extracted from "на <слово>" (RU) or "for/on <word>" (EN);
  defaults to "разное" / "misc".

Time math:
- Day boundary: local-calendar midnight via os.time({year,month,day,...}).
- Week boundary: rolling 7×86400 seconds.

Pack count: 98 → 99 functional.

resources/commands/expenses/breakdown.lua

@@ -0,0 +1,55 @@
+-- Per-category breakdown for the last 7 days, sorted by amount desc.
+
+local lang = jarvis.context.language
+local raw_state = jarvis.state.get("entries") or ""
+if raw_state == "" then
+    return jarvis.cmd.not_found(lang == "ru"
+        and "Нечего разбивать, сэр."
+        or  "Nothing to break down, sir.")
+end
+
+local now = jarvis.context.time
+local now_ts = os.time({
+    year = now.year, month = now.month, day = now.day,
+    hour = now.hour, min = now.minute, sec = now.second or 0,
+})
+local cutoff = now_ts - 7 * 86400
+
+local by_cat = {}
+for chunk in raw_state:gmatch("([^|]+)") do
+    local ts, am, ca = chunk:match("^(%d+),([%-%d%.]+),(.+)$")
+    ts = tonumber(ts); am = tonumber(am)
+    if ts and am and ts >= cutoff then
+        by_cat[ca] = (by_cat[ca] or 0) + am
+    end
+end
+
+local rows = {}
+for ca, total in pairs(by_cat) do
+    table.insert(rows, { ca = ca, total = total })
+end
+table.sort(rows, function(a, b) return a.total > b.total end)
+
+if #rows == 0 then
+    return jarvis.cmd.ok(lang == "ru"
+        and "На этой неделе тишина по тратам, сэр."
+        or  "Quiet week on spending, sir.")
+end
+
+-- Top 5 categories spoken; rest collapses into "и другое"
+local top = math.min(5, #rows)
+local parts = {}
+for i = 1, top do
+    table.insert(parts, string.format("%s %.0f", rows[i].ca, rows[i].total))
+end
+local tail = ""
+if #rows > top then
+    local rest_total = 0
+    for i = top + 1, #rows do rest_total = rest_total + rows[i].total end
+    tail = string.format(lang == "ru"
+        and " и другое %.0f" or " and other %.0f", rest_total)
+end
+
+return jarvis.cmd.ok(string.format(lang == "ru"
+    and "По категориям: %s%s."
+    or  "By category: %s%s.", table.concat(parts, ", "), tail))