fix(dolt): server mode should support multi-process access

Code review fix: In server mode, Dolt connects to an external sql-server
and should NOT be single-process-only. The whole point of server mode is
to enable multi-writer access.

Changes:
- Add Config.GetCapabilities() method that considers server mode
- Update daemon_guard, daemon_autostart, daemons, main to use GetCapabilities()
- Add TestGetCapabilities test
- Update init command help text to document server mode flags

The existing CapabilitiesForBackend(string) is kept for backward compatibility
but now includes a note to use Config.GetCapabilities() when the full config
is available.

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

cmd/bd/daemon_autostart.go

@@ -69,7 +69,8 @@ func singleProcessOnlyBackend() bool {
 	if err != nil || cfg == nil {
 		return false
 	}
-	return configfile.CapabilitiesForBackend(cfg.GetBackend()).SingleProcessOnly
+	// Use GetCapabilities() to properly handle Dolt server mode
+	return cfg.GetCapabilities().SingleProcessOnly
 }
 
 // shouldAutoStartDaemon checks if daemon auto-start is enabled

cmd/bd/daemon_guard.go

@@ -69,9 +69,9 @@ func guardDaemonStartForDolt(cmd *cobra.Command, _ []string) error {
 		return nil
 	}
 
-	backend := cfg.GetBackend()
-	if configfile.CapabilitiesForBackend(backend).SingleProcessOnly {
-		return fmt.Errorf("%s", singleProcessBackendHelp(backend))
+	// Use GetCapabilities() to properly handle Dolt server mode
+	if cfg.GetCapabilities().SingleProcessOnly {
+		return fmt.Errorf("%s", singleProcessBackendHelp(cfg.GetBackend()))
 	}
 
 	return nil

cmd/bd/daemons.go

@@ -255,11 +255,12 @@ Stops the daemon gracefully, then starts a new one.`,
 		}
 		workspace := targetDaemon.WorkspacePath
 
-		// Guardrail: don't (re)start daemons for single-process backends (e.g., Dolt).
+		// Guardrail: don't (re)start daemons for single-process backends (e.g., embedded Dolt).
 		// This command may be run from a different workspace, so check the target workspace.
+		// Note: Dolt server mode supports multi-process, so GetCapabilities() is used.
 		targetBeadsDir := beads.FollowRedirect(filepath.Join(workspace, ".beads"))
 		if cfg, err := configfile.Load(targetBeadsDir); err == nil && cfg != nil {
-			if configfile.CapabilitiesForBackend(cfg.GetBackend()).SingleProcessOnly {
+			if cfg.GetCapabilities().SingleProcessOnly {
 				if jsonOutput {
 					outputJSON(map[string]string{"error": fmt.Sprintf("daemon mode is not supported for backend %q (single-process only)", cfg.GetBackend())})
 				} else {

cmd/bd/init.go

@@ -40,7 +40,12 @@ to prevent deleted issues from being resurrected during re-initialization.
 With --stealth: configures per-repository git settings for invisible beads usage:
   • .git/info/exclude to prevent beads files from being committed
   • Claude Code settings with bd onboard instruction
-  Perfect for personal use without affecting repo collaborators.`,
+  Perfect for personal use without affecting repo collaborators.
+
+With --backend dolt --server: configures Dolt to connect to an external dolt sql-server
+instead of using the embedded driver. This enables multi-writer access for multi-agent
+environments. Connection settings can be customized with --server-host, --server-port,
+and --server-user. Password should be set via BEADS_DOLT_PASSWORD environment variable.`,
 	Run: func(cmd *cobra.Command, _ []string) {
 		prefix, _ := cmd.Flags().GetString("prefix")
 		quiet, _ := cmd.Flags().GetBool("quiet")

cmd/bd/main.go

@@ -623,13 +623,14 @@ var rootCmd = &cobra.Command{
 			debug.Logf("wisp operation detected, using direct mode")
 		}
 
-		// Dolt backend (embedded) is single-process-only; never use daemon/RPC.
+		// Embedded Dolt is single-process-only; never use daemon/RPC.
+		// (Dolt server mode supports multi-process and won't trigger this.)
 		// This must be checked after dbPath is resolved.
 		if !noDaemon && singleProcessOnlyBackend() {
 			noDaemon = true
 			daemonStatus.AutoStartEnabled = false
 			daemonStatus.FallbackReason = FallbackSingleProcessOnly
-			daemonStatus.Detail = "backend is single-process-only (dolt): daemon mode disabled; using direct mode"
+			daemonStatus.Detail = "backend is single-process-only (embedded dolt): daemon mode disabled; using direct mode"
 			debug.Logf("single-process backend detected, using direct mode")
 		}
 

internal/configfile/configfile.go

@@ -176,17 +176,35 @@ type BackendCapabilities struct {
 
 // CapabilitiesForBackend returns capabilities for a backend string.
 // Unknown backends are treated conservatively as single-process-only.
+//
+// Note: For Dolt, this returns SingleProcessOnly=true for embedded mode.
+// Use Config.GetCapabilities() when you have the full config to properly
+// handle server mode (which supports multi-process access).
 func CapabilitiesForBackend(backend string) BackendCapabilities {
 	switch strings.TrimSpace(strings.ToLower(backend)) {
 	case "", BackendSQLite:
 		return BackendCapabilities{SingleProcessOnly: false}
 	case BackendDolt:
+		// Embedded Dolt is single-process-only.
+		// Server mode is handled by Config.GetCapabilities().
 		return BackendCapabilities{SingleProcessOnly: true}
 	default:
 		return BackendCapabilities{SingleProcessOnly: true}
 	}
 }
 
+// GetCapabilities returns the backend capabilities for this config.
+// Unlike CapabilitiesForBackend(string), this considers Dolt server mode
+// which supports multi-process access.
+func (c *Config) GetCapabilities() BackendCapabilities {
+	backend := c.GetBackend()
+	if backend == BackendDolt && c.IsDoltServerMode() {
+		// Server mode supports multi-writer, so NOT single-process-only
+		return BackendCapabilities{SingleProcessOnly: false}
+	}
+	return CapabilitiesForBackend(backend)
+}
+
 // GetBackend returns the configured backend type, defaulting to SQLite.
 func (c *Config) GetBackend() string {
 	if c.Backend == "" {

internal/configfile/configfile_test.go

@@ -338,6 +338,45 @@ func TestDoltServerMode(t *testing.T) {
 	})
 }
 
+// TestGetCapabilities tests that GetCapabilities properly handles server mode
+func TestGetCapabilities(t *testing.T) {
+	tests := []struct {
+		name           string
+		cfg            *Config
+		wantSingleProc bool
+	}{
+		{
+			name:           "sqlite is multi-process",
+			cfg:            &Config{Backend: BackendSQLite},
+			wantSingleProc: false,
+		},
+		{
+			name:           "dolt embedded is single-process",
+			cfg:            &Config{Backend: BackendDolt, DoltMode: DoltModeEmbedded},
+			wantSingleProc: true,
+		},
+		{
+			name:           "dolt default (empty) is single-process",
+			cfg:            &Config{Backend: BackendDolt},
+			wantSingleProc: true,
+		},
+		{
+			name:           "dolt server mode is multi-process",
+			cfg:            &Config{Backend: BackendDolt, DoltMode: DoltModeServer},
+			wantSingleProc: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := tt.cfg.GetCapabilities().SingleProcessOnly
+			if got != tt.wantSingleProc {
+				t.Errorf("GetCapabilities().SingleProcessOnly = %v, want %v", got, tt.wantSingleProc)
+			}
+		})
+	}
+}
+
 // TestDoltServerModeRoundtrip tests that server mode config survives save/load
 func TestDoltServerModeRoundtrip(t *testing.T) {
 	tmpDir := t.TempDir()