feat(federation): add dolt sql-server mode for daemon (bd-wkumz.2)

Add --federation flag to bd daemon start that runs dolt sql-server
instead of the embedded driver. Enables multi-writer support and
exposes remotesapi on port 8080 for peer-to-peer push/pull.

Changes:
- Add --federation flag to daemon start command
- Create dolt server manager (internal/storage/dolt/server.go)
- Update DoltStore to support server mode via MySQL protocol
- Integrate server lifecycle into daemon (auto-start/stop)
- Add tests for server management and server mode connections

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/storage/dolt/server_integration_test.go

@@ -0,0 +1,122 @@
+package dolt
+
+import (
+	"context"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/steveyegge/beads/internal/types"
+)
+
+// TestServerModeConnection tests connecting to DoltStore via server mode
+func TestServerModeConnection(t *testing.T) {
+	// Skip if dolt is not available
+	if _, err := exec.LookPath("dolt"); err != nil {
+		t.Skip("dolt not installed, skipping server mode test")
+	}
+
+	// Create temp directory for test
+	tmpDir, err := os.MkdirTemp("", "dolt-server-mode-test-*")
+	if err != nil {
+		t.Fatalf("failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Initialize dolt repo
+	cmd := exec.Command("dolt", "init")
+	cmd.Dir = tmpDir
+	if err := cmd.Run(); err != nil {
+		t.Fatalf("failed to init dolt repo: %v", err)
+	}
+
+	// Start server on non-standard ports
+	server := NewServer(ServerConfig{
+		DataDir:        tmpDir,
+		SQLPort:        13307,
+		RemotesAPIPort: 18081,
+		Host:           "127.0.0.1",
+		LogFile:        filepath.Join(tmpDir, "server.log"),
+	})
+
+	ctx, cancel := context.WithTimeout(context.Background(), 120*time.Second)
+	defer cancel()
+
+	if err := server.Start(ctx); err != nil {
+		t.Fatalf("failed to start server: %v", err)
+	}
+	defer func() {
+		if err := server.Stop(); err != nil {
+			t.Logf("warning: failed to stop server: %v", err)
+		}
+	}()
+
+	// Connect using server mode
+	store, err := New(ctx, &Config{
+		Path:       tmpDir,
+		Database:   "beads",
+		ServerMode: true,
+		ServerHost: "127.0.0.1",
+		ServerPort: 13307,
+	})
+	if err != nil {
+		t.Fatalf("failed to create server mode store: %v", err)
+	}
+	defer store.Close()
+
+	// Set issue prefix (required for creating issues)
+	if err := store.SetConfig(ctx, "issue_prefix", "test"); err != nil {
+		t.Fatalf("failed to set issue_prefix: %v", err)
+	}
+
+	// Verify we can perform basic operations
+	// Create an issue
+	issue := &types.Issue{
+		Title:       "Test issue in server mode",
+		Description: "Original description",
+		Status:      types.StatusOpen,
+		Priority:    2,
+		IssueType:   types.TypeTask,
+	}
+	if err := store.CreateIssue(ctx, issue, "test"); err != nil {
+		t.Fatalf("failed to create issue: %v", err)
+	}
+	if issue.ID == "" {
+		t.Fatal("expected issue ID to be generated")
+	}
+	t.Logf("Created issue: %s", issue.ID)
+
+	// Read it back
+	readIssue, err := store.GetIssue(ctx, issue.ID)
+	if err != nil {
+		t.Fatalf("failed to get issue: %v", err)
+	}
+	if readIssue.Title != issue.Title {
+		t.Errorf("title mismatch: expected %q, got %q", issue.Title, readIssue.Title)
+	}
+
+	// Update it
+	updates := map[string]interface{}{
+		"description": "Updated description",
+		"priority":    1,
+	}
+	if err := store.UpdateIssue(ctx, issue.ID, updates, "test"); err != nil {
+		t.Fatalf("failed to update issue: %v", err)
+	}
+
+	// Verify update
+	updatedIssue, err := store.GetIssue(ctx, issue.ID)
+	if err != nil {
+		t.Fatalf("failed to get updated issue: %v", err)
+	}
+	if updatedIssue.Description != "Updated description" {
+		t.Errorf("expected description 'Updated description', got %q", updatedIssue.Description)
+	}
+	if updatedIssue.Priority != 1 {
+		t.Errorf("expected priority 1, got %d", updatedIssue.Priority)
+	}
+
+	t.Logf("Server mode connection test passed: created and updated issue %s", issue.ID)
+}