mavend: give the voice handler a CoreAPI that can serve the day plan

wireVoice runs before the tick loop exists, so it could only be handed
the bare store adapter — and that adapter answers DayPlan with "not
available via direct store API", because a day plan is assembled by the
tick loop and is not a table to read. So queryDayPlan, which the query
chain reaches for "какие у меня планы на сегодня", failed for every
caller on the deployed daemon.

main already back-patches the other direction (daemonAPI.chatFn =
handler.handleText). This is the same seam in reverse, at both wiring
sites. No recursion risk: nothing in the voice path calls api.Chat.

With the plan reachable, it recited its reminders as literal JSON. The
payload unwrapper existed but was private to the phraser, so the day
plan had its own non-unwrapping copy. One owner now, store.ReminderText,
with the phraser delegating to it.

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

cmd/mavend/main.go

@@ -341,6 +341,9 @@ func run(args []string) error {
 		if voiceW != nil && voiceW.handler != nil {
 			api := coreAPI.(*daemonAPI)
 			api.chatFn = voiceW.handler.handleText
+			// And the reverse: the handler was wired with the bare store
+			// adapter, which cannot serve the day plan. See upgradeAPI.
+			voiceW.handler.upgradeAPI(api)
 		}
 		if voiceW != nil && voiceW.mcp != nil {
 			coreAPI.(*daemonAPI).getMCPServers = voiceW.mcp.status
@@ -603,6 +606,7 @@ func run(args []string) error {
 			}
 			if voiceW != nil && voiceW.handler != nil {
 				newAPI.chatFn = voiceW.handler.handleText
+				voiceW.handler.upgradeAPI(newAPI)
 			}
 			srv.SetAPI(newAPI)
 			srv.Check = (&auth.Gate{Enrollment: auth.NewFloorEnrollment(), Session: passkeySess}).Check