Unify cache polling on CACHE_STATUS and split API docs.

Replace separate accel/tap snapshot UART commands with one clients[] response
that omits unsubscribed fields; remove snapshot handlers and CLI commands.
Add goTool/docs for WebSocket streams and REST; tap-snapshot REST uses CACHE_STATUS.

Co-authored-by: Cursor <cursoragent@cursor.com>

goTool/cmd_tap.go

@@ -44,32 +44,6 @@ func runTapNotify(sp *serialPort, args []string) error {
 	return nil
 }
 
-func runTapSnapshot(sp *serialPort, args []string) error {
-	fs := flag.NewFlagSet("tap", flag.ExitOnError)
-	clientID := fs.Uint("client", 0, "client id (0 = all slaves with tap notify)")
-	if err := fs.Parse(args); err != nil {
-		return err
-	}
-	return runTapSnapshotForClient(sp, uint32(*clientID))
-}
-
-func runTapSnapshotForClient(sp *serialPort, clientID uint32) error {
-	r, err := sp.readTapSnapshot(clientID)
-	if err != nil {
-		return err
-	}
-	events := r.GetEvents()
-	if len(events) == 0 {
-		fmt.Println("no tap events (none pending or older than 16 ms)")
-		return nil
-	}
-	for _, e := range events {
-		fmt.Printf("client %d: %s (age %d ms)\n",
-			e.GetClientId(), tapKindLabel(e.GetKind()), e.GetAgeMs())
-	}
-	return nil
-}
-
 func tapKindLabel(k pb.TapKind) string {
 	switch k {
 	case pb.TapKind_TAP_SINGLE: