WIP: Extract daemon runtime into internal/daemonrunner

- Created config.go with Config struct
- Created daemon.go with Daemon struct and Start/Stop methods
- Created logger.go for logging setup
- Created process.go for lock/PID management
- Created fingerprint.go for database validation
- Created flock_unix.go/flock_windows.go for platform-specific locking
- Created git.go for git operations

Still TODO:
- Implement runGlobalDaemon, startRPCServer, runSyncLoop
- Create sync.go, rpc.go, jsonl.go, validation.go
- Update cmd/bd/daemon.go to use daemonrunner

Part of bd-5f26

internal/daemonrunner/config.go

@@ -0,0 +1,26 @@
+package daemonrunner
+
+import "time"
+
+// Config holds all configuration for the daemon
+type Config struct {
+	// Sync behavior
+	Interval   time.Duration
+	AutoCommit bool
+	AutoPush   bool
+
+	// Scope
+	Global bool
+
+	// Paths
+	LogFile   string
+	PIDFile   string
+	DBPath    string // Local daemon only
+	BeadsDir  string // Local daemon: .beads dir, Global daemon: ~/.beads
+
+	// RPC
+	SocketPath string
+
+	// Workspace
+	WorkspacePath string // Only for local daemon: parent of .beads directory
+}