confirm answers match whole words from the lexicon (V-567)

classifyConfirm was a substring test over bare stems, so "погода",
"дальше", "надо" and "давление" all read as "да", and "покажи" and
"около" read as "ок". resolveConfirm runs before routing, so a question
about the weather executed a parked destructive act. Reproduced on the box:
with "restart nonexistent-xyz" parked, "какая погода" answered "не
получилось выполнить команду".

The yes and no answers are now two closed sets in internal/lexicon, matched
as whole tokens longest-first, and the WHOLE utterance must be answer words
and filler — a leading "давай" does not make "давай посмотрим погоду" an
answer. Anything else is confirmUnknown, which now leaves the confirm parked
instead of disarming it: an utterance that is not an answer is not a
cancellation either.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

cmd/mavend/confirm.go

@@ -3,9 +3,13 @@ package main
 import (
 	"context"
 	"log"
+	"slices"
+	"sort"
 	"strings"
 	"time"
+	"unicode"
 
+	"github.com/kami/maven/internal/lexicon"
 	"github.com/kami/maven/internal/phraser"
 	"github.com/kami/maven/internal/router"
 )
@@ -57,10 +61,18 @@ func (h *reactiveHandler) park(fn string, args []string, phrase string) {
 // resolveConfirm interprets an utterance as the answer to a parked destructive
 // act OR a parked routine proposal. Returns (reply, true) when it consumed the
 // utterance as a y/n answer; ("", false) when there's nothing pending (or the
-// parked act expired), so the caller routes the utterance normally. An
-// unrecognised answer cancels the pending and routes normally — a confirm that
-// can't be answered clearly is safer abandoned than left armed.
+// parked act expired), so the caller routes the utterance normally.
+//
+// An utterance that is not clearly yes or no is not an answer at all, so it is
+// handed straight back and the pending stays parked until it expires (V-567).
+// This resolver runs before routing and holds the most dangerous trigger on the
+// box; it may only claim a turn it is certain about.
 func (h *reactiveHandler) resolveConfirm(ctx context.Context, text string) (string, bool) {
+	verdict := classifyConfirm(text)
+	if verdict == confirmUnknown {
+		return "", false
+	}
+
 	h.mu.Lock()
 	defer h.mu.Unlock()
 
@@ -68,16 +80,12 @@ func (h *reactiveHandler) resolveConfirm(ctx context.Context, text string) (stri
 		if !r.claim() {
 			continue
 		}
-		// The slot is already cleared by claim(): every branch below drops the
-		// pending, including the unclear one — a confirm that can't be
-		// answered clearly is safer abandoned than left armed.
-		switch classifyConfirm(text) {
+		// The slot is already cleared by claim().
+		switch verdict {
 		case confirmYes:
 			return r.yes(), true
-		case confirmNo:
-			return r.no(), true
 		default:
-			return "", false
+			return r.no(), true
 		}
 	}
 	return "", false
@@ -194,23 +202,92 @@ const (
 	confirmNo
 )
 
-// classifyConfirm reads a short ru/en yes-or-no answer. Substring match on the
-// stems so inflections/fillers ("да, давай", "нет, отмени") still land.
+// confirmWords are the two closed sets, tokenized once and ordered
+// longest-first so "не надо" is read before "нет" could claim any of it.
+var (
+	confirmYesPhrases = confirmPhrases(lexicon.ConfirmYes())
+	confirmNoPhrases  = confirmPhrases(lexicon.ConfirmNo())
+)
+
+// confirmPhrases splits each lexicon member into tokens and sorts the result
+// longest-first, so a walk that tries them in order matches the longest member
+// that fits.
+func confirmPhrases(words []string) [][]string {
+	out := make([][]string, 0, len(words))
+	for _, w := range words {
+		if toks := confirmTokens(w); len(toks) > 0 {
+			out = append(out, toks)
+		}
+	}
+	sort.SliceStable(out, func(i, j int) bool { return len(out[i]) > len(out[j]) })
+	return out
+}
+
+// confirmTokens splits an utterance into lowercase word tokens. Punctuation and
+// spacing are separators; an apostrophe is not, because "don't" is one word.
+func confirmTokens(text string) []string {
+	return strings.FieldsFunc(strings.ToLower(text), func(r rune) bool {
+		if r == '\'' || r == '’' {
+			return false
+		}
+		return !unicode.IsLetter(r) && !unicode.IsDigit(r)
+	})
+}
+
+// classifyConfirm reads a short ru/en yes-or-no answer to a parked confirm.
+//
+// The whole utterance must consist of confirmation words and filler, matched as
+// whole tokens against the closed lexicon sets. Anything else is
+// confirmUnknown, which leaves the confirm parked and routes the turn — see
+// resolveConfirm. Both halves of that are the fix for V-567: this used to be a
+// substring test over bare stems, so "погода", "дальше", "надо" and "давление"
+// all read as "да", and "покажи" and "около" read as "ок". A parked destructive
+// act fired on a question about the weather.
+//
+// Requiring the WHOLE utterance is the second half. A leading confirm word does
+// not make a sentence an answer: "давай посмотрим погоду" opens a request, and
+// the only safe reading of a sentence that carries its own subject is that he
+// moved on. Guessing wrong here executes something; guessing wrong the other way
+// asks again.
 func classifyConfirm(text string) confirmVerdict {
-	t := strings.ToLower(strings.TrimSpace(text))
-	// negatives first — "не надо" contains no "да", but check no-stems before
-	// yes so a leading "нет" isn't shadowed.
-	for _, no := range []string{"нет", "не надо", "отмен", "стоп", "no", "cancel", "stop", "don't"} {
-		if strings.Contains(t, no) {
+	tokens := confirmTokens(text)
+	if len(tokens) == 0 {
+		return confirmUnknown
+	}
+	verdict := confirmUnknown
+	for i := 0; i < len(tokens); {
+		// Negatives first: "не надо" and "не хочу" open with a token that is
+		// not itself an answer, and a yes hit must never shadow them.
+		if n := matchConfirm(confirmNoPhrases, tokens[i:]); n > 0 {
 			return confirmNo
 		}
+		if n := matchConfirm(confirmYesPhrases, tokens[i:]); n > 0 {
+			verdict, i = confirmYes, i+n
+			continue
+		}
+		if lexicon.IsFillerParticle(tokens[i]) {
+			i++
+			continue
+		}
+		// A word that is neither an answer nor filler carries a subject of its
+		// own, so this utterance is not an answer to her question.
+		return confirmUnknown
 	}
-	for _, yes := range []string{"да", "ага", "давай", "подтвер", "конечно", "yes", "yeah", "yep", "confirm", "ок", "okay", "ok"} {
-		if strings.Contains(t, yes) {
-			return confirmYes
+	return verdict
+}
+
+// matchConfirm reports the length of the longest phrase matching at the head of
+// tokens, or 0.
+func matchConfirm(phrases [][]string, tokens []string) int {
+	for _, p := range phrases {
+		if len(p) > len(tokens) {
+			continue
+		}
+		if slices.Equal(p, tokens[:len(p)]) {
+			return len(p)
 		}
 	}
-	return confirmUnknown
+	return 0
 }
 
 // actPhrase renders "fn arg1 arg2" for the confirm prompt.