quiet: the noun form and the comparative are commands too

The pre-route toggle knew "тихий режим" and every negation of it, but not
the two phrasings that get spoken most: "включи режим тишины" (the setting
named as a noun) and "сделай потише". Both fell through to the router,
which has no quiet intent, so the command did nothing at all.

Adds those as stem pairs, plus a quietWordStems list so the
negated-but-unmatched fallback recognises "хватит тишины" the way it
already recognised "хватит тихого режима".

Locks the English phrasings from the routing fixture in the test table
("turn quiet mode back on", "turn off quiet mode", "stop quiet mode") —
all three already behaved, none were covered.

"на улице стало потише" and "в тишине лучше думается" stay inert: a
single-word pattern still only matches a single-word utterance.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TrVSBKe3RFDF4fGYKWYQnX

cmd/mavend/quiet_toggle_test.go

@@ -47,6 +47,15 @@ func TestResolveQuietToggle(t *testing.T) {
 		{"побудь в тихом режиме", quietOn},
 		{"Тихий Режим!", quietOn},
 		{"тихая", quietOn},
+		// The noun form and the comparative.
+		{"включи режим тишины", quietOn},
+		{"режим тишины", quietOn},
+		{"сделай потише", quietOn},
+		{"сделай тише", quietOn},
+		{"потише", quietOn},
+		// English, as the fixture phrases it.
+		{"turn quiet mode back on", quietOn},
+		{"enable quiet mode", quietOn},
 
 		// OFF vocabulary — all seven, incl. the three that used to say ON.
 		{"quiet off", quietOff},
@@ -60,6 +69,12 @@ func TestResolveQuietToggle(t *testing.T) {
 		{"выключи тихий режим", quietOff},
 		{"отмени тихий режим пожалуйста", quietOff},
 		{"верни громкий режим", quietOff},
+		{"выключи режим тишины", quietOff},
+		{"хватит тишины", quietOff},
+		{"turn off quiet mode", quietOff},
+		{"quiet mode off", quietOff},
+		{"stop quiet mode", quietOff},
+		{"disable quiet mode", quietOff},
 
 		// False positives: "тихо"/"тихий" as ordinary Russian.
 		{"очень тихий сегодня день", quietNone},
@@ -68,6 +83,8 @@ func TestResolveQuietToggle(t *testing.T) {
 		{"потихоньку", quietNone},
 		{"тихонько", quietNone},
 		{"он говорил тихим голосом весь вечер", quietNone},
+		{"в тишине лучше думается", quietNone},
+		{"на улице стало потише", quietNone},
 
 		// Unrelated.
 		{"напомни завтра позвонить маме", quietNone},