refactor(instance): remove container image label support

docs/docs/reference/images/overview.md

@@ -113,7 +113,3 @@ For complete image specifications, see the Dockerfiles in the repository:
 - [Base Dockerfile](https://github.com/GilmanLab/headjack/blob/master/images/base/Dockerfile)
 - [Systemd Dockerfile](https://github.com/GilmanLab/headjack/blob/master/images/systemd/Dockerfile)
 - [Docker-in-Docker Dockerfile](https://github.com/GilmanLab/headjack/blob/master/images/dind/Dockerfile)
-
-## See Also
-
-- [OCI Labels](labels.md) - Labels for custom image configuration

docs/sidebars.ts

@@ -118,7 +118,6 @@ const sidebars: SidebarsConfig = {
           },
           items: [
             'reference/images/overview',
-            'reference/images/labels',
           ],
         },
       ],

images/systemd/Dockerfile

@@ -43,17 +43,5 @@ STOPSIGNAL SIGRTMIN+3
 # Volume for cgroups (required for systemd)
 VOLUME ["/sys/fs/cgroup"]
 
-# =============================================================================
-# Headjack Runtime Configuration Labels
-# =============================================================================
-
-# These labels inform Headjack how to run the image:
-# - io.headjack.init: Command to run as PID 1 (overrides "sleep infinity" default)
-# - io.headjack.podman.flags: Space-separated key=value pairs for Podman flags
-# - io.headjack.docker.flags: Space-separated key=value pairs for Docker flags
-LABEL io.headjack.init="/lib/systemd/systemd"
-LABEL io.headjack.podman.flags="systemd=always"
-LABEL io.headjack.docker.flags="privileged=true cgroupns=host volume=/sys/fs/cgroup:/sys/fs/cgroup:rw"
-
 # systemd as init system
 CMD ["/lib/systemd/systemd"]

internal/cmd/root.go

@@ -21,7 +21,6 @@ import (
 	"github.com/jmgilman/headjack/internal/git"
 	"github.com/jmgilman/headjack/internal/instance"
 	"github.com/jmgilman/headjack/internal/multiplexer"
-	"github.com/jmgilman/headjack/internal/registry"
 )
 
 // baseDeps lists the external binaries that must always be available.
@@ -176,19 +175,16 @@ func initManager() error {
 	// Use tmux as the terminal multiplexer
 	mux := multiplexer.NewTmux(executor)
 
-	// Create registry client for fetching image metadata
-	regClient := registry.NewClient(registry.ClientConfig{})
-
 	// Map runtime name to RuntimeType
 	runtimeType := runtimeNameToType(runtimeName)
 
-	// Parse config flags for merging with image label flags
+	// Parse config flags
 	configFlags, err := getConfigFlags()
 	if err != nil {
 		return err
 	}
 
-	mgr = instance.NewManager(store, runtime, opener, mux, regClient, instance.ManagerConfig{
+	mgr = instance.NewManager(store, runtime, opener, mux, instance.ManagerConfig{
 		WorktreesDir: worktreesDir,
 		LogsDir:      logsDir,
 		RuntimeType:  runtimeType,

internal/flags/flags.go

@@ -5,7 +5,6 @@ import (
 	"errors"
 	"fmt"
 	"sort"
-	"strings"
 )
 
 // Flags represents runtime flags as a key-value map.
@@ -55,61 +54,6 @@ func FromConfig(cfg map[string]any) (Flags, error) {
 	return result, nil
 }
 
-// FromLabel parses a space-separated string of key=value pairs into Flags.
-// Format: "key1=value1 key2=value2 boolkey=true barekey"
-//
-// Rules:
-//   - "key=value" → string value
-//   - "key=true" or "key=false" → bool value
-//   - "key" (bare, no =) → bool true
-//   - Repeated keys become []string (e.g., "vol=/a vol=/b" → {"vol": ["/a", "/b"]})
-//   - Values containing = are handled correctly (splits on first = only)
-func FromLabel(label string) (Flags, error) {
-	result := make(Flags)
-	if label == "" {
-		return result, nil
-	}
-
-	for _, part := range strings.Fields(label) {
-		key, value, hasEquals := strings.Cut(part, "=")
-		if key == "" {
-			continue // Skip empty keys
-		}
-
-		if !hasEquals {
-			// Bare key treated as boolean true (e.g., "privileged")
-			result[key] = true
-			continue
-		}
-
-		// Check for boolean string values
-		switch strings.ToLower(value) {
-		case "true":
-			result[key] = true
-			continue
-		case "false":
-			result[key] = false
-			continue
-		}
-
-		// Handle repeated keys by converting to array
-		if existing, ok := result[key]; ok {
-			switch e := existing.(type) {
-			case string:
-				result[key] = []string{e, value}
-			case []string:
-				result[key] = append(e, value)
-			default:
-				// Overwrite non-string values (e.g., bool) with the new string
-				result[key] = value
-			}
-		} else {
-			result[key] = value
-		}
-	}
-	return result, nil
-}
-
 // Merge combines two Flags maps with override taking precedence.
 // Keys in override replace keys in base.
 func Merge(base, override Flags) Flags {