Add prefix/suffix support, short ID fallback, unit docs

- config: add Prefix/Suffix fields to Config struct
- systemd: ServiceName/Generate/UnitPath/Install/Uninstall/Enable/Disable/Status all accept prefix+suffix
- runtime: fall back to short container ID (12 chars) when container has no name
- cmd: active, status, install all thread prefix/suffix from config
- systemd/generator_test.go: updated all calls + added TestGenerate_WithPrefixSuffix
- docs/generated-units.md: full examples of every unit type + ordering + naming
- README: updated config docs, prefix/suffix section, link to docs/

cmd/install.go

@@ -31,6 +31,7 @@ func runInstall(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
+	prefix, suffix := cfg.Prefix, cfg.Suffix
 	installed := 0
 	skipped := 0
 	removed := 0
@@ -38,14 +39,14 @@ func runInstall(cmd *cobra.Command, args []string) error {
 	for _, u := range cfg.Units {
 		if !u.Enabled {
 			// Remove unit file if it exists for disabled units
-			if systemd.IsInstalled(u) {
+			if systemd.IsInstalled(u, prefix, suffix) {
 				if dryRun {
-					fmt.Printf("  ~ would remove: %s\n", systemd.ServiceName(u))
+					fmt.Printf("  ~ would remove: %s\n", systemd.ServiceName(u, prefix, suffix))
 				} else {
-					if err := systemd.Uninstall(u); err != nil {
+					if err := systemd.Uninstall(u, prefix, suffix); err != nil {
 						fmt.Printf("  ✗ failed to remove %s: %v\n", u.Name, err)
 					} else {
-						fmt.Printf("  - removed: %s (disabled)\n", systemd.ServiceName(u))
+						fmt.Printf("  - removed: %s (disabled)\n", systemd.ServiceName(u, prefix, suffix))
 						removed++
 					}
 				}
@@ -56,21 +57,21 @@ func runInstall(cmd *cobra.Command, args []string) error {
 		}
 
 		if dryRun {
-			content, err := systemd.Generate(u)
+			content, err := systemd.Generate(u, prefix, suffix)
 			if err != nil {
 				fmt.Printf("  ✗ %s: %v\n", u.Name, err)
 				continue
 			}
-			path, _ := systemd.UnitPath(u)
+			path, _ := systemd.UnitPath(u, prefix, suffix)
 			fmt.Printf("\n--- %s ---\n%s\n", path, content)
 			installed++
 			continue
 		}
 
-		if err := systemd.Install(u); err != nil {
+		if err := systemd.Install(u, prefix, suffix); err != nil {
 			fmt.Printf("  ✗ failed: %s: %v\n", u.Name, err)
 		} else {
-			path, _ := systemd.UnitPath(u)
+			path, _ := systemd.UnitPath(u, prefix, suffix)
 			fmt.Printf("  ✓ installed: %s\n", path)
 			installed++
 		}