feat(daemon): add GET /status endpoint (bd-148)

- Add OpStatus operation and StatusResponse type to RPC protocol
- Add workspacePath and dbPath fields to Server struct
- Implement handleStatus() handler with daemon metadata
- Track last activity time with atomic.Value
- Add client.Status() method
- Check for exclusive locks via ShouldSkipDatabase()
- Update all test files to use new NewServer signature
- Add comprehensive status endpoint test

Closes bd-148

internal/rpc/status_test.go

@@ -0,0 +1,85 @@
+package rpc
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/steveyegge/beads/internal/storage/sqlite"
+)
+
+func TestStatusEndpoint(t *testing.T) {
+	tmpDir := t.TempDir()
+	dbPath := filepath.Join(tmpDir, "test.db")
+	socketPath := filepath.Join(tmpDir, "test.sock")
+
+	store, err := sqlite.New(dbPath)
+	if err != nil {
+		t.Fatalf("failed to create storage: %v", err)
+	}
+	defer store.Close()
+
+	server := NewServer(socketPath, store, tmpDir, dbPath)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	go func() {
+		_ = server.Start(ctx)
+	}()
+
+	<-server.WaitReady()
+	defer server.Stop()
+
+	client, err := TryConnect(socketPath)
+	if err != nil {
+		t.Fatalf("failed to connect: %v", err)
+	}
+	if client == nil {
+		t.Fatal("client is nil")
+	}
+	defer client.Close()
+
+	// Test status endpoint
+	status, err := client.Status()
+	if err != nil {
+		t.Fatalf("status call failed: %v", err)
+	}
+
+	// Verify response fields
+	if status.Version == "" {
+		t.Error("expected version to be set")
+	}
+	if status.WorkspacePath != tmpDir {
+		t.Errorf("expected workspace path %s, got %s", tmpDir, status.WorkspacePath)
+	}
+	if status.DatabasePath != dbPath {
+		t.Errorf("expected database path %s, got %s", dbPath, status.DatabasePath)
+	}
+	if status.SocketPath != socketPath {
+		t.Errorf("expected socket path %s, got %s", socketPath, status.SocketPath)
+	}
+	if status.PID != os.Getpid() {
+		t.Errorf("expected PID %d, got %d", os.Getpid(), status.PID)
+	}
+	if status.UptimeSeconds <= 0 {
+		t.Error("expected positive uptime")
+	}
+	if status.LastActivityTime == "" {
+		t.Error("expected last activity time to be set")
+	}
+	if status.ExclusiveLockActive {
+		t.Error("expected no exclusive lock in test")
+	}
+
+	// Verify last activity time is recent
+	lastActivity, err := time.Parse(time.RFC3339, status.LastActivityTime)
+	if err != nil {
+		t.Errorf("failed to parse last activity time: %v", err)
+	}
+	if time.Since(lastActivity) > 5*time.Second {
+		t.Errorf("last activity time too old: %v", lastActivity)
+	}
+}