feat: add [runners] config section to toggle each runner on/off

Adds RunnersConfig{Claude,Gemini,Local,Container *bool} to Config,
parsed from a [runners] TOML section. Each field uses the *bool pointer
pattern (nil = enabled by default, false = disabled) so existing installs
require no config changes.

serve.go / run.go now gate each runner registration on the corresponding
Enabled() method. The pool's runners map remains the authoritative
routing table — absent entries are already skipped by pickAgent and
fail-fast in getRunner, so no executor changes are needed.

Example:
  [runners]
  gemini = false   # disable cloud gemini runner
  local  = true    # explicit (same as default)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

4 files changed, 127 insertions, 16 deletions

diff --git a/internal/cli/run.go b/internal/cli/run.go
index 48f34b7..771c7b7 100644
--- a/internal/cli/run.go
+++ b/internal/cli/run.go
@@ -77,8 +77,10 @@ func runTasks(file string, parallel int, dryRun bool) error {
 		apiURL = "http://" + cfg.ServerAddr
 	}
 
-	runners := map[string]executor.Runner{
-		"claude": &executor.ContainerRunner{
+	runners := map[string]executor.Runner{}
+
+	if cfg.Runners.ClaudeEnabled() {
+		runners["claude"] = &executor.ContainerRunner{
 			Image:        cfg.ClaudeImage,
 			Logger:       logger,
 			LogDir:       cfg.LogDir,
@@ -87,8 +89,10 @@ func runTasks(file string, parallel int, dryRun bool) error {
 			SSHAuthSock:  cfg.SSHAuthSock,
 			ClaudeBinary: cfg.ClaudeBinaryPath,
 			GeminiBinary: cfg.GeminiBinaryPath,
-		},
-		"gemini": &executor.ContainerRunner{
+		}
+	}
+	if cfg.Runners.GeminiEnabled() {
+		runners["gemini"] = &executor.ContainerRunner{
 			Image:        cfg.GeminiImage,
 			Logger:       logger,
 			LogDir:       cfg.LogDir,
@@ -97,11 +101,11 @@ func runTasks(file string, parallel int, dryRun bool) error {
 			SSHAuthSock:  cfg.SSHAuthSock,
 			ClaudeBinary: cfg.ClaudeBinaryPath,
 			GeminiBinary: cfg.GeminiBinaryPath,
-		},
+		}
 	}
 
 	localClient := buildLocalLLMClient(cfg.LocalModel, logger)
-	if localClient != nil {
+	if localClient != nil && cfg.Runners.LocalEnabled() {
 		runners["local"] = &executor.LocalRunner{
 			Client:             localClient,
 			Logger:             logger,
diff --git a/internal/cli/serve.go b/internal/cli/serve.go
index 459c35b..dae66d6 100644
--- a/internal/cli/serve.go
+++ b/internal/cli/serve.go
@@ -79,10 +79,12 @@ func serve(addr string) error {
 	claudeConfigDir := cfg.ClaudeConfigDir
 
 	repoDir, _ := os.Getwd()
-	runners := map[string]executor.Runner{
-		// ContainerRunner: binaries are resolved via PATH inside the container image,
-		// so ClaudeBinary/GeminiBinary are left empty (host paths would not exist inside).
-		"claude": &executor.ContainerRunner{
+	runners := map[string]executor.Runner{}
+
+	// ContainerRunner: binaries are resolved via PATH inside the container image,
+	// so ClaudeBinary/GeminiBinary are left empty (host paths would not exist inside).
+	if cfg.Runners.ClaudeEnabled() {
+		runners["claude"] = &executor.ContainerRunner{
 			Image:             cfg.ClaudeImage,
 			Logger:            logger,
 			LogDir:            cfg.LogDir,
@@ -92,8 +94,10 @@ func serve(addr string) error {
 			ClaudeConfigDir:   claudeConfigDir,
 			CredentialSyncCmd: filepath.Join(repoDir, "scripts", "sync-credentials"),
 			Store:             store,
-		},
-		"gemini": &executor.ContainerRunner{
+		}
+	}
+	if cfg.Runners.GeminiEnabled() {
+		runners["gemini"] = &executor.ContainerRunner{
 			Image:             cfg.GeminiImage,
 			Logger:            logger,
 			LogDir:            cfg.LogDir,
@@ -103,8 +107,10 @@ func serve(addr string) error {
 			ClaudeConfigDir:   claudeConfigDir,
 			CredentialSyncCmd: filepath.Join(repoDir, "scripts", "sync-credentials"),
 			Store:             store,
-		},
-		"container": &executor.ContainerRunner{
+		}
+	}
+	if cfg.Runners.ContainerEnabled() {
+		runners["container"] = &executor.ContainerRunner{
 			Image:             "claudomator-agent:latest",
 			Logger:            logger,
 			LogDir:            cfg.LogDir,
@@ -114,11 +120,11 @@ func serve(addr string) error {
 			ClaudeConfigDir:   claudeConfigDir,
 			CredentialSyncCmd: filepath.Join(repoDir, "scripts", "sync-credentials"),
 			Store:             store,
-		},
+		}
 	}
 
 	localClient := buildLocalLLMClient(cfg.LocalModel, logger)
-	if localClient != nil {
+	if localClient != nil && cfg.Runners.LocalEnabled() {
 		runners["local"] = &executor.LocalRunner{
 			Client:             localClient,
 			Logger:             logger,
diff --git a/internal/config/config.go b/internal/config/config.go
index 25187cf..892d3f7 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -45,6 +45,24 @@ func (m LocalModel) UseForElaborate() bool {
 	return *m.PreferForElaborate
 }
 
+// RunnersConfig controls which agent runners are registered. Each field is a
+// *bool so that nil (absent from TOML) means "enabled by default", while an
+// explicit false disables the runner without affecting others.
+//
+// The local runner also requires LocalModel.Endpoint to be set; setting
+// Local = true without an endpoint has no effect.
+type RunnersConfig struct {
+	Claude    *bool `toml:"claude"`
+	Gemini    *bool `toml:"gemini"`
+	Local     *bool `toml:"local"`
+	Container *bool `toml:"container"`
+}
+
+func (r RunnersConfig) ClaudeEnabled() bool    { return r.Claude == nil || *r.Claude }
+func (r RunnersConfig) GeminiEnabled() bool    { return r.Gemini == nil || *r.Gemini }
+func (r RunnersConfig) LocalEnabled() bool     { return r.Local == nil || *r.Local }
+func (r RunnersConfig) ContainerEnabled() bool { return r.Container == nil || *r.Container }
+
 type Config struct {
 	DataDir          string        `toml:"data_dir"`
 	DBPath           string        `toml:"-"`
@@ -68,6 +86,7 @@ type Config struct {
 	VAPIDEmail       string        `toml:"vapid_email"`
 	ClaudeConfigDir  string        `toml:"claude_config_dir"`
 	LocalModel       LocalModel    `toml:"local_model"`
+	Runners          RunnersConfig `toml:"runners"`
 }
 
 func Default() (*Config, error) {
diff --git a/internal/config/config_test.go b/internal/config/config_test.go
index e4f1a5d..0d47ca0 100644
--- a/internal/config/config_test.go
+++ b/internal/config/config_test.go
@@ -54,6 +54,88 @@ func TestLoadFile_MissingFile_ReturnsError(t *testing.T) {
 	}
 }
 
+func TestRunnersConfig_DefaultsAllEnabled(t *testing.T) {
+	r := RunnersConfig{}
+	if !r.ClaudeEnabled() {
+		t.Error("claude should be enabled by default (nil)")
+	}
+	if !r.GeminiEnabled() {
+		t.Error("gemini should be enabled by default (nil)")
+	}
+	if !r.LocalEnabled() {
+		t.Error("local should be enabled by default (nil)")
+	}
+	if !r.ContainerEnabled() {
+		t.Error("container should be enabled by default (nil)")
+	}
+}
+
+func TestRunnersConfig_ExplicitFalseDisables(t *testing.T) {
+	f := false
+	r := RunnersConfig{Claude: &f, Gemini: &f, Local: &f, Container: &f}
+	if r.ClaudeEnabled() {
+		t.Error("explicit false should disable claude")
+	}
+	if r.GeminiEnabled() {
+		t.Error("explicit false should disable gemini")
+	}
+	if r.LocalEnabled() {
+		t.Error("explicit false should disable local")
+	}
+	if r.ContainerEnabled() {
+		t.Error("explicit false should disable container")
+	}
+}
+
+func TestRunnersConfig_ExplicitTrueEnables(t *testing.T) {
+	tr := true
+	r := RunnersConfig{Claude: &tr, Gemini: &tr, Local: &tr, Container: &tr}
+	if !r.ClaudeEnabled() || !r.GeminiEnabled() || !r.LocalEnabled() || !r.ContainerEnabled() {
+		t.Error("explicit true should keep all runners enabled")
+	}
+}
+
+func TestRunnersConfig_MixedToggles(t *testing.T) {
+	f, tr := false, true
+	r := RunnersConfig{Claude: &tr, Gemini: &f, Local: &tr}
+	if !r.ClaudeEnabled() {
+		t.Error("claude should be enabled")
+	}
+	if r.GeminiEnabled() {
+		t.Error("gemini should be disabled")
+	}
+	if !r.LocalEnabled() {
+		t.Error("local should be enabled")
+	}
+	if !r.ContainerEnabled() {
+		t.Error("container should be enabled (nil = default)")
+	}
+}
+
+func TestRunnersConfig_TOMLRoundTrip(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "config.toml")
+	toml := "[runners]\ngemini = false\n"
+	if err := os.WriteFile(path, []byte(toml), 0600); err != nil {
+		t.Fatal(err)
+	}
+	t.Setenv("HOME", dir)
+
+	cfg, err := LoadFile(path)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if cfg.Runners.GeminiEnabled() {
+		t.Error("gemini should be disabled after TOML load")
+	}
+	if !cfg.Runners.ClaudeEnabled() {
+		t.Error("claude should remain enabled (not in TOML)")
+	}
+	if !cfg.Runners.LocalEnabled() {
+		t.Error("local should remain enabled (not in TOML)")
+	}
+}
+
 func TestLocalModel_UseForElaborate_EmptyEndpoint(t *testing.T) {
 	m := LocalModel{}
 	if m.UseForElaborate() {