Read spending from zenmoney in the poller, answer it from facts (#125)

The trust boundary is zenmoney, not maven — they already hold his bank
sessions. So the poller reads /v8/diff/ and writes totals as
facts(kind=env, source=poll:zenmoney); core reads those back when he asks
and never sees the token.

internal/zenmoney sums transactions per currency over a window, skipping
tombstoned rows and transfers between his own accounts, and refuses to
encode a summary built from zero transactions. That refusal is the whole
design: a failed or empty read writes nothing and leaves the last good
total alone, because a zero recited as fact is worse than silence. No
currency conversion either — a figure he can check against his bank beats
one he cannot.

Off unless configured, and the token is read from a FILE rather than a
flag so it never lands in `ps`, in docker-compose.yml, or in shell
history. Nothing about the money is search input, no tick rule reads the
keys, and the log lines name keys, never figures.

The live-credential half is BLOCKED: there is no zenmoney account or token
here, so everything is verified against a recorded diff fixture.

internal/router/money.go

@@ -0,0 +1,71 @@
+package router
+
+import "strings"
+
+// Money questions, matched deterministically (Vikunja #125).
+//
+// No new intent, for the same reason as tasks: the intent enum is a contract
+// with the relabelling prompt. "сколько я потратил?" is a query; which figure
+// it asks for is a lookup, not something to ask a 1.7B — and a model asked to
+// invent a spending total will happily do it.
+
+// MoneyWindow — which period a money question asks about.
+type MoneyWindow int
+
+const (
+	MoneyNone MoneyWindow = iota
+	MoneyToday
+	MoneyMonth
+)
+
+// moneyNouns — the words that make a question be about his money.
+var moneyNouns = []string{
+	"потратил", "потратила", "тратил", "траты", "трат", "расходы", "расходов",
+	"заработал", "потрачено", "денег", "spend", "spent", "expenses",
+}
+
+// ParseMoneyQuery reports whether an utterance asks about spending or income,
+// and over which window. Defaults to the month: "сколько я потратил?" without a
+// period is the month-to-date question, which is the one worth answering.
+//
+// Narrow on purpose. A money noun alone is not enough — "я потратил весь день
+// на это" is him talking about his day, so an amount word or an explicit
+// question word has to be there too.
+func ParseMoneyQuery(text string) (MoneyWindow, bool) {
+	toks := planTokens(text)
+	if len(toks) == 0 {
+		return MoneyNone, false
+	}
+	hasNoun := false
+	for _, t := range toks {
+		for _, n := range moneyNouns {
+			if t == n {
+				hasNoun = true
+			}
+		}
+	}
+	if !hasNoun {
+		return MoneyNone, false
+	}
+	// "весь день", "время", "силы" — spending that is not money.
+	for _, t := range toks {
+		switch t {
+		case "день", "дня", "время", "времени", "силы", "сил", "нервы":
+			return MoneyNone, false
+		}
+	}
+	asking := hasTok(toks, "сколько") || hasTok(toks, "какие") || hasTok(toks, "покажи") ||
+		hasTok(toks, "how") || hasTok(toks, "much") || hasTok(toks, "my") ||
+		hasTok(toks, "мои") || hasTok(toks, "траты") || hasTok(toks, "расходы")
+	if !asking {
+		return MoneyNone, false
+	}
+	lower := strings.ToLower(text)
+	switch {
+	case hasTok(toks, "сегодня") || strings.Contains(lower, "today"):
+		return MoneyToday, true
+	case hasTok(toks, "месяц") || hasTok(toks, "месяце") || strings.Contains(lower, "month"):
+		return MoneyMonth, true
+	}
+	return MoneyMonth, true
+}

internal/router/money_test.go

@@ -0,0 +1,31 @@
+package router
+
+import "testing"
+
+func TestParseMoneyQuery(t *testing.T) {
+	cases := []struct {
+		in     string
+		window MoneyWindow
+		ok     bool
+	}{
+		{"сколько я потратил сегодня?", MoneyToday, true},
+		{"сколько я потратил в этом месяце?", MoneyMonth, true},
+		{"сколько я потратил?", MoneyMonth, true}, // month-to-date by default
+		{"покажи мои траты", MoneyMonth, true},
+		{"какие у меня расходы за месяц", MoneyMonth, true},
+		{"how much did I spend today", MoneyToday, true},
+		{"сколько я заработал в этом месяце", MoneyMonth, true},
+		// Not about money.
+		{"я потратил весь день на это", MoneyNone, false},
+		{"потратил много сил", MoneyNone, false},
+		{"какая погода?", MoneyNone, false},
+		{"я купил молоко", MoneyNone, false},
+		{"", MoneyNone, false},
+	}
+	for _, c := range cases {
+		w, ok := ParseMoneyQuery(c.in)
+		if ok != c.ok || w != c.window {
+			t.Errorf("ParseMoneyQuery(%q) = (%v, %v), want (%v, %v)", c.in, w, ok, c.window, c.ok)
+		}
+	}
+}