Add watcher tests, refactor watch() to accept context

- Added watcher_test.go: 10 tests covering create, write, remove,
  rename, ignored files, debouncing, directory creation/removal,
  and manifest updates
- Refactored watch() to accept context.Context for clean cancellation
- Added signal handling (SIGINT/SIGTERM) for graceful shutdown in main.go
- Fixed test expectations (version two = 11 bytes, not 10)

1 files changed, 5 insertions, 1 deletions

diff --git a/watcher.go b/watcher.go
index 7b823da..2b56bb4 100644
--- a/watcher.go
+++ b/watcher.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"context"
 	"log"
 	"os"
 	"path/filepath"
@@ -12,7 +13,7 @@ import (
 	ignore "github.com/sabhiram/go-gitignore"
 )
 
-func watch(hostDir, dataDir string, manifest *Manifest, rules *ignore.GitIgnore, dryRun, verbose bool) error {
+func watch(ctx context.Context, hostDir, dataDir string, manifest *Manifest, rules *ignore.GitIgnore, dryRun, verbose bool) error {
 	watcher, err := fsnotify.NewWatcher()
 	if err != nil {
 		return err
@@ -28,6 +29,9 @@ func watch(hostDir, dataDir string, manifest *Manifest, rules *ignore.GitIgnore,
 
 	for {
 		select {
+		case <-ctx.Done():
+			return nil
+
 		case event, ok := <-watcher.Events:
 			if !ok {
 				return nil