feat(daemon): add auto_pull config parameter for periodic remote sync

Add --auto-pull flag to control whether the daemon periodically pulls from
remote to check for updates from other clones.

Configuration precedence:
1. --auto-pull CLI flag (highest)
2. BEADS_AUTO_PULL environment variable
3. daemon.auto_pull in database config
4. Default: true when sync.branch is configured

When auto_pull is enabled, the daemon creates a remoteSyncTicker that
periodically calls doAutoImport() to pull remote changes. When disabled,
users must manually run 'git pull' to sync remote changes.

Changes:
- cmd/bd/daemon.go: Add --auto-pull flag and config reading logic
- cmd/bd/daemon_event_loop.go: Gate remoteSyncTicker on autoPull parameter
- cmd/bd/daemon_lifecycle.go: Add auto-pull to status output and spawn args
- internal/rpc/protocol.go: Add AutoPull field to StatusResponse
- internal/rpc/server_core.go: Add autoPull to Server struct and SetConfig
- internal/rpc/server_routing_validation_diagnostics.go: Include in status
- Tests updated to pass autoPull parameter

Closes #TBD

internal/rpc/server_core.go

@@ -57,6 +57,7 @@ type Server struct {
 	// Daemon configuration (set via SetConfig after creation)
 	autoCommit   bool
 	autoPush     bool
+	autoPull     bool
 	localMode    bool
 	syncInterval string
 	daemonMode   string
@@ -159,11 +160,12 @@ func (s *Server) MutationChan() <-chan MutationEvent {
 }
 
 // SetConfig sets the daemon configuration for status reporting
-func (s *Server) SetConfig(autoCommit, autoPush, localMode bool, syncInterval, daemonMode string) {
+func (s *Server) SetConfig(autoCommit, autoPush, autoPull, localMode bool, syncInterval, daemonMode string) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	s.autoCommit = autoCommit
 	s.autoPush = autoPush
+	s.autoPull = autoPull
 	s.localMode = localMode
 	s.syncInterval = syncInterval
 	s.daemonMode = daemonMode