feat: IPC additions for reminders/events/routines, ack tracking, tool management

- Extend IPC wire protocol: add ListReminders, ListEvents, ListProposedRoutines,
  DismissProposedRoutine, AcceptProposedRoutine IPC methods with request/response
  types. Update wire.go with new message kinds.
- Add ack_sends table (migration #5): tracks sev4 telegram repeat-til-ack
  delivery state with rule name + timestamp, indexed for dedup.
- Add Store.DeleteTool: permanently removes a tool row (for dismissing proposed
  tools), idempotent on missing tool.
- Update tick.go: wire new IPC handlers into daemon tick.

cmd/mavend/tick.go

@@ -10,6 +10,7 @@ package main
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"log"
 	"os"
@@ -440,6 +441,14 @@ func (t *tickLoop) trace() *loop.TickTrace {
 type daemonAPI struct {
 	ipc.CoreAPI
 	getTrace func() *loop.TickTrace
+	chatFn   func(ctx context.Context, text string) string
+}
+
+func (d *daemonAPI) Chat(ctx context.Context, text string) (string, error) {
+	if d.chatFn == nil {
+		return "", errors.New("mavend: chat not available")
+	}
+	return d.chatFn(ctx, text), nil
 }
 
 func (d *daemonAPI) TickTrace(ctx context.Context) (ipc.TickTrace, error) {