Add Windows native watcher with Unix socket IPC

Architecture:
- Windows binary: watches files via ReadDirectoryChangesW (fsnotify),
  sends events as newline-delimited JSON over Unix domain socket
- Container: performs initial sync, then listens on socket for events
  from Windows watcher

New files:
- cmd_windows.go: Windows serve command (watcher + socket server)
- cmd_linux.go: Linux socket client + event listener
- types.go: shared FileEvent, FileMeta, Manifest types
- watcher_test_helper.go: inotify-based watcher for integration tests

Changes:
- main.go: simplified to just call run()
- watcher.go: removed fsnotify dependency, extracted Watcher interface
- sync.go: removed duplicate type definitions
- watcher_test.go: uses watchForTests() helper

Usage:
  sourcewatch.exe -dir C:\myproject -socket D:\sourcewatch.sock
  docker run -v D:\sourcewatch.sock:/run/sourcewatch.sock \
             -v C:\myproject:/host:ro -v mydata:/data sourcewatch

1 files changed, 1 insertions, 54 deletions

diff --git a/main.go b/main.go
index 570890d..ffee7e4 100644
--- a/main.go
+++ b/main.go
@@ -1,58 +1,5 @@
 package main
 
-import (
-	"context"
-	"flag"
-	"log"
-	"os"
-	"os/signal"
-	"syscall"
-)
-
-var (
-	hostDir  = flag.String("host", "/host", "Host source directory (read-only)")
-	dataDir  = flag.String("data", "/data", "Data destination directory")
-	verbose  = flag.Bool("verbose", false, "Enable verbose logging (shorthand for -log-level debug)")
-	logLevel = flag.String("log-level", "info", "Log level: debug, info, warn, error, none")
-	dryRun   = flag.Bool("dry-run", false, "Preview what would be synced without copying")
-)
-
 func main() {
-	flag.Parse()
-
-	if *verbose {
-		*logLevel = "debug"
-	}
-
-	level, err := ParseLogLevel(*logLevel)
-	if err != nil {
-		log.Fatal(err)
-	}
-	SetLogLevel(level)
-
-	log.SetFlags(0)
-	log.SetOutput(nil)
-
-	stack := NewGitignoreStack(*hostDir)
-
-	manifest, err := initialSync(*hostDir, *dataDir, stack, *dryRun)
-	if err != nil {
-		logErrorf("initial sync failed: %v", err)
-		os.Exit(1)
-	}
-
-	if *dryRun {
-		logInfo("dry-run complete, exiting")
-		return
-	}
-
-	logInfo("watcher: ready, monitoring for changes ...")
-
-	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
-	defer cancel()
-
-	if err := watch(ctx, *hostDir, *dataDir, manifest, stack, *dryRun); err != nil {
-		logErrorf("watcher failed: %v", err)
-		os.Exit(1)
-	}
+	run()
 }