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>

cmd/bd/daemon_lifecycle.go

@@ -369,7 +369,7 @@ func stopAllDaemons() {
 }
 
 // startDaemon starts the daemon (in foreground if requested, otherwise background)
-func startDaemon(interval time.Duration, autoCommit, autoPush, autoPull, localMode, foreground bool, logFile, pidFile, logLevel string, logJSON bool) {
+func startDaemon(interval time.Duration, autoCommit, autoPush, autoPull, localMode, foreground bool, logFile, pidFile, logLevel string, logJSON, federation bool) {
 	logPath, err := getLogFilePath(logFile)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
@@ -385,7 +385,7 @@ func startDaemon(interval time.Duration, autoCommit, autoPush, autoPull, localMo
 
 	// Run in foreground if --foreground flag set or if we're the forked child process
 	if foreground || os.Getenv("BD_DAEMON_FOREGROUND") == "1" {
-		runDaemonLoop(interval, autoCommit, autoPush, autoPull, localMode, logPath, pidFile, logLevel, logJSON)
+		runDaemonLoop(interval, autoCommit, autoPush, autoPull, localMode, logPath, pidFile, logLevel, logJSON, federation)
 		return
 	}
 
@@ -419,6 +419,9 @@ func startDaemon(interval time.Duration, autoCommit, autoPush, autoPull, localMo
 	if logJSON {
 		args = append(args, "--log-json")
 	}
+	if federation {
+		args = append(args, "--federation")
+	}
 
 	cmd := exec.Command(exe, args...) // #nosec G204 - bd daemon command from trusted binary
 	cmd.Env = append(os.Environ(), "BD_DAEMON_FOREGROUND=1")