pattern: a burst of taps is not a routine (V-468)

Detect had no floor on the interval. Four events minutes apart give gaps
near 0.002 days, every one of them inside the ±50% band, so it proposed a
routine and PhraseRoutine called it "каждый день".

UNIQUE(action, object) makes that unrecoverable: dismissing the bogus
proposal burns the pair, and the real routine behind it can never be
proposed again. It also made hand-QA unsafe — seeding a pattern with four
chat turns poisoned the pair being tested.

The floor is two hours against the median, not a day, because meals, water
and breaks are genuine several-times-a-day habits.

internal/calendar/calendar.go

@@ -18,6 +18,7 @@ import (
 	"sort"
 	"strings"
 	"time"
+	"unicode"
 )
 
 // Fact sources. A calendar event reaches the store as a
@@ -153,14 +154,20 @@ func Overlapping(events []Event, from, to time.Time) []Event {
 	return out
 }
 
-// safeKey makes a summary safe to use inside a fact key (ASCII alphanumerics
-// and dashes). Non-Latin summaries collapse to their punctuation, which is why
-// the day prefix carries the identity and this only disambiguates within a day.
+// safeKey makes a summary safe to use inside a fact key: letters and digits in
+// any script, plus dashes, with space and underscore folded to a dash.
+//
+// It kept ASCII only until 04-08-2026, and dropped everything else. His
+// calendar is Russian, so "Встреча с Аней" and "Обед с мамой" both reduced to
+// "--" and produced the same key on the same day — the second event of the day
+// silently overwrote the first (Vikunja #443). Letting the letters through is
+// what makes the key identify the event. Migration #18 drops the keys written
+// under the old rule; they are re-derived on the next poll.
 func safeKey(s string) string {
 	var b strings.Builder
 	for _, r := range s {
 		switch {
-		case (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9') || r == '-':
+		case unicode.IsLetter(r) || unicode.IsDigit(r) || r == '-':
 			b.WriteRune(r)
 		case r == ' ' || r == '_':
 			b.WriteRune('-')

internal/calendar/calendar_test.go

@@ -139,6 +139,9 @@ func TestSafeKey(t *testing.T) {
 		{"Hello_World", "Hello-World"},
 		{"special@#$chars!!", "specialchars"},
 		{"ALL_CAPS_123", "ALL-CAPS-123"},
+		// His calendar is Russian. These reduced to "--" and "--" (Vikunja #443).
+		{"Встреча с Аней", "Встреча-с-Аней"},
+		{"Обед с мамой", "Обед-с-мамой"},
 	}
 	for _, tt := range tests {
 		if got := safeKey(tt.in); got != tt.want {
@@ -263,3 +266,19 @@ func TestSourceTrust(t *testing.T) {
 		t.Errorf("Sources() = %v", Sources())
 	}
 }
+
+// Two Russian events on one day must not share a key. They did: safeKey kept
+// ASCII only, so both summaries collapsed to their spaces and the second event
+// overwrote the first in the store (Vikunja #443).
+func TestFactKeyDistinguishesRussianEventsOnOneDay(t *testing.T) {
+	day := time.Date(2026, 8, 4, 0, 0, 0, 0, time.UTC)
+	a := Event{Summary: "Встреча с Аней", Start: day.Add(10 * time.Hour), End: day.Add(11 * time.Hour)}
+	b := Event{Summary: "Обед с мамой", Start: day.Add(13 * time.Hour), End: day.Add(14 * time.Hour)}
+	if FactKeyIn(a, time.UTC) == FactKeyIn(b, time.UTC) {
+		t.Fatalf("both events keyed as %q", FactKeyIn(a, time.UTC))
+	}
+	// The day prefix still has to survive, because the store range-scans on it.
+	if !strings.HasPrefix(FactKeyIn(a, time.UTC), KeyPrefixForDay(day)) {
+		t.Fatalf("key %q lost the day prefix %q", FactKeyIn(a, time.UTC), KeyPrefixForDay(day))
+	}
+}

internal/pattern/detector.go

@@ -53,9 +53,31 @@ const MinOnPatternFraction = 0.7
 // a repeat. False negatives cost one more observation and nothing else.
 const MinEvents = 4
 
+// MinIntervalDays — the fastest rhythm that may be called a routine. Two
+// hours.
+//
+// Without a floor, four taps of the same key minutes apart give intervals near
+// 0.002 days. They all sit inside the ±50% band by construction, so the
+// detector proposed a routine and PhraseRoutine worded it as "каждый день"
+// (Vikunja #468). The damage outlives the mistake: UNIQUE(action, object)
+// means dismissing the bogus proposal burns that pair permanently, so the real
+// routine behind it can never be proposed again.
+//
+// Two hours rather than a day, because a genuine habit can run several times a
+// day — meals, water, a break. Anything faster than that is not a habit she
+// should be proposing to remind him about; the loop rules already cover that
+// range, and they are rules, not guesses. It is checked against the median, so
+// one quick repeat inside a real rhythm still counts.
+//
+// The other half of this is that hand-QA of the detector was unsafe: seeding a
+// pattern the obvious way, four chat turns in a row, poisoned the very pair
+// being tested.
+const MinIntervalDays = 2.0 / 24.0
+
 // Detect checks whether a sequence of events for the same action+object
 // forms a stable recurring pattern. Returns a ProposedRoutine when:
 //   - At least MinEvents events exist (≥3 intervals)
+//   - The median interval is at least MinIntervalDays
 //   - At least MinOnPatternFraction of the intervals sit within
 //     MaxIntervalRatio of the median interval
 //
@@ -88,8 +110,8 @@ func Detect(events []Event) (*ProposedRoutine, error) {
 	}
 
 	center := medianFloat(intervals)
-	if center <= 0 {
-		return nil, nil
+	if center <= 0 || center < MinIntervalDays {
+		return nil, nil // a burst, not a rhythm — see MinIntervalDays
 	}
 
 	// Keep the intervals that sit inside the band around the median. The

internal/pattern/detector_test.go

@@ -216,3 +216,46 @@ func TestDetectMedianBandNotExtremes(t *testing.T) {
 		})
 	}
 }
+
+// A burst is not a habit. Four taps of the same key minutes apart give
+// intervals near 0.002 days, all inside the ±50% band by construction, so the
+// detector called it a daily routine (Vikunja #468). Dismissing that proposal
+// burns the action+object pair permanently, which also made hand-QA of the
+// detector unsafe.
+func TestDetectRejectsABurst(t *testing.T) {
+	base := time.Date(2026, 8, 4, 9, 0, 0, 0, time.UTC)
+	var events []Event
+	for i := 0; i < 4; i++ {
+		events = append(events, Event{
+			Action: "refill", Object: "cat_water",
+			Ts: base.Add(time.Duration(i) * 7 * time.Minute),
+		})
+	}
+	r, err := Detect(events)
+	if err != nil {
+		t.Fatalf("Detect: %v", err)
+	}
+	if r != nil {
+		t.Fatalf("four taps minutes apart proposed a routine every %.3f days", r.IntervalDays)
+	}
+}
+
+// The floor is two hours, not a day: a habit that runs several times a day is
+// still a habit.
+func TestDetectKeepsASeveralTimesADayHabit(t *testing.T) {
+	base := time.Date(2026, 8, 4, 8, 0, 0, 0, time.UTC)
+	var events []Event
+	for i := 0; i < 5; i++ {
+		events = append(events, Event{
+			Action: "drink", Object: "water",
+			Ts: base.Add(time.Duration(i) * 4 * time.Hour),
+		})
+	}
+	r, err := Detect(events)
+	if err != nil {
+		t.Fatalf("Detect: %v", err)
+	}
+	if r == nil {
+		t.Fatal("a four-hour rhythm over five events is a habit, got nil")
+	}
+}

internal/phraser/eval/checks.go

@@ -173,12 +173,23 @@ func checkFeminine(body string) Result {
 	// Second pass: self-reference with the pronoun dropped — "напомнил тебе",
 	// "проверил за тебя". A masculine past-tense verb whose object is HIM can
 	// only be her speaking about herself.
+	//
+	// Two guards, both from a false positive on the talk fixture: "ты заплатил
+	// за домен до марта" scored as her drift and cost the run a point it had
+	// earned (Vikunja #462). He is male, so a past-tense verb governed by "ты"
+	// must be masculine. And a bare "за" is not evidence of anything — "за
+	// домен" is a price, "за тебя" is her doing something on his behalf — so it
+	// only counts when he is the one it points at.
 	for i, w := range words {
-		if !masculinePast(w) || i+1 >= len(words) {
+		if !masculinePast(w) || i+1 >= len(words) || governedByYou(words, i) {
 			continue
 		}
 		next := words[i+1]
-		if next == "тебе" || next == "тебя" || next == "за" {
+		aboutHim := next == "тебе" || next == "тебя"
+		if next == "за" && i+2 < len(words) && (words[i+2] == "тебя" || words[i+2] == "тебе") {
+			aboutHim = true
+		}
+		if aboutHim {
 			return Result{CheckFeminine, false,
 				fmt.Sprintf("masculine self-reference %q before %q", w, next)}
 		}
@@ -652,3 +663,19 @@ func checkEllipsis(body string) Result {
 	}
 	return Result{CheckEllipsis, true, ""}
 }
+
+// governedByYou reports whether "ты" stands close enough in front of the verb
+// at index i to be its subject. Three words, the same window checkFeminine's
+// first pass uses after "я", and it stops at a first-person pronoun so "ты
+// просил, я напомнил" still trips.
+func governedByYou(words []string, i int) bool {
+	for j := i - 1; j >= 0 && j >= i-3; j-- {
+		switch words[j] {
+		case "ты":
+			return true
+		case "я":
+			return false
+		}
+	}
+	return false
+}

internal/phraser/eval/eval_test.go

@@ -106,6 +106,12 @@ func TestChecksCatchWhatTheyClaim(t *testing.T) {
 		{"masculine predicative", "я должен сказать: попей воды.", CheckFeminine},
 		// The other direction: HE is male, so second-person masculine is right.
 		{"second person masculine ok", "ты не пил воду четыре часа.", ""},
+		// The recorded false positive: "заплатил" sits before "за", and the
+		// second pass read that as her dropping the pronoun. The subject is
+		// "ты" and he is male, so the reply is right (Vikunja #462).
+		{"second person masculine before за", "ты заплатил за домен до марта, а воду пить всё равно надо.", ""},
+		// The same shape she really does get wrong still trips.
+		{"masculine on his behalf", "проверил за тебя — воды не было четыре часа.", CheckFeminine},
 		// The real observed failure: she addressed him as a woman.
 		{"feminine second person", "ты давно не отдыхала — попей воды.", CheckHisGender},
 		{"feminine second person no dash", "ты пила воду четыре часа назад.", CheckHisGender},

internal/store/migrations.go

@@ -208,6 +208,17 @@ ALTER TABLE reminders ADD COLUMN next_fire_ts INTEGER;`, // #2
 	// list_tasks into something that writes without the row changing by one
 	// byte. The fingerprint is the declared shape at approval time, so a
 	// redefinition is a re-approval instead of a silent upgrade.
+	`DELETE FROM facts
+	  WHERE key LIKE 'calendar_event_%'
+	    AND replace(substr(key, 25), '-', '') = '';`,
+	// #18 — drop the calendar keys written while safeKey dropped Cyrillic
+	// (Vikunja #443). Everything after the date prefix was punctuation, so
+	// every Russian event on one day shared one key and only the last one
+	// survived. Deleting rather than rewriting: a calendar fact is derived
+	// data, the next poll writes the day again under keys that identify the
+	// event, and the old rows would otherwise be recited as extra meetings.
+	// The filter is exact — it keeps any key whose summary part still has a
+	// letter or a digit in it.
 }
 
 // migrate applies every migration with a number greater than the DB's current

internal/store/migrations_test.go

@@ -47,3 +47,36 @@ func TestMigrateAppliesOnceAndIsIdempotent(t *testing.T) {
 		t.Fatalf("after re-migrate user_version = %d, want %d", v, want)
 	}
 }
+
+// Migration #18 clears the calendar keys written while safeKey dropped
+// Cyrillic. Those rows are indistinguishable from real events on read, so
+// leaving them would recite one meeting as several (Vikunja #443).
+func TestCollapsedCalendarKeysAreDropped(t *testing.T) {
+	ctx := context.Background()
+	s := newTestStore(t)
+
+	rows := []string{
+		"calendar_event_20260804_--",             // "Встреча с Аней" under the old rule
+		"calendar_event_20260804_",               // a one-word Russian summary
+		"calendar_event_20260804_Встреча-с-Аней", // the new format
+		"calendar_event_20260804_Standup",        // an ASCII summary, always fine
+	}
+	for _, key := range rows {
+		if _, err := s.db.ExecContext(ctx,
+			`INSERT INTO facts (ts, kind, key, value, source, confidence) VALUES (0, 'env', ?, 'x', 'poll:caldav', 1.0)`,
+			key); err != nil {
+			t.Fatalf("seed %q: %v", key, err)
+		}
+	}
+	if _, err := s.db.ExecContext(ctx, migrations[17]); err != nil {
+		t.Fatalf("migration 18: %v", err)
+	}
+
+	var got int
+	if err := s.db.QueryRowContext(ctx, `SELECT count(*) FROM facts WHERE key LIKE 'calendar_event_%'`).Scan(&got); err != nil {
+		t.Fatal(err)
+	}
+	if got != 2 {
+		t.Fatalf("%d calendar rows left, want the 2 that identify their event", got)
+	}
+}