feat(#1957): wire gh-identity plugin into workspace-server

Ships the monorepo side of molecule-core#1957 (agent identity collapse).
Companion to molecule-ai-plugin-gh-identity (new repo, merged-and-tagged
separately).

Changes:
- manifest.json: add gh-identity plugin to Tier 1 registry
- workspace-server/go.mod: require github.com/Molecule-AI/molecule-ai-plugin-gh-identity
- cmd/server/main.go: build a shared provisionhook.Registry, register
  gh-identity first (always), then github-app-auth (gated on GITHUB_APP_ID)
- workspace_provision.go: propagate workspace.Role into
  env["MOLECULE_AGENT_ROLE"] before calling the mutator chain, so the
  gh-identity plugin can see which agent is booting
- provisionhook/mutator.go: add Registry.Mutators() accessor so
  individual-plugin registries can be merged onto a shared one at boot

Boot log gains a line like:
  env-mutator chain: [gh-identity github-app-auth]

Effect per workspace:
- env contains MOLECULE_AGENT_ROLE, MOLECULE_OWNER, MOLECULE_ATTRIBUTION_BADGE,
  MOLECULE_GH_WRAPPER_B64, MOLECULE_GH_WRAPPER_SHA
- Each workspace template's install.sh can decode + install the wrapper at
  /usr/local/bin/gh, intercepting @me assignment and prepending agent
  attribution on PR/issue creates

Does not break existing workspaces — absent workspace.role, the plugin is
a no-op. Absent install.sh updates in each template, the env vars are
simply unused.

Follow-up template PRs (hermes, claude-code, langgraph, etc.) each add
~15 lines to install.sh to decode + install the wrapper.

Ref: #1957

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

manifest.json

@@ -4,6 +4,7 @@
   "plugins": [
     {"name": "browser-automation", "repo": "Molecule-AI/molecule-ai-plugin-browser-automation", "ref": "main"},
     {"name": "ecc", "repo": "Molecule-AI/molecule-ai-plugin-ecc", "ref": "main"},
+    {"name": "gh-identity", "repo": "Molecule-AI/molecule-ai-plugin-gh-identity", "ref": "main"},
     {"name": "molecule-audit", "repo": "Molecule-AI/molecule-ai-plugin-molecule-audit", "ref": "main"},
     {"name": "molecule-audit-trail", "repo": "Molecule-AI/molecule-ai-plugin-molecule-audit-trail", "ref": "main"},
     {"name": "molecule-careful-bash", "repo": "Molecule-AI/molecule-ai-plugin-molecule-careful-bash", "ref": "main"},

workspace-server/cmd/server/main.go

@@ -23,10 +23,13 @@ import (
 	"github.com/Molecule-AI/molecule-monorepo/platform/internal/supervised"
 	"github.com/Molecule-AI/molecule-monorepo/platform/internal/ws"
 
-	// External plugin — registers an EnvMutator that injects GITHUB_TOKEN /
-	// GH_TOKEN from a GitHub App installation token. Soft-dep: only active
-	// when GITHUB_APP_ID env var is set (see main() for the gate).
-	pluginloader "github.com/Molecule-AI/molecule-ai-plugin-github-app-auth/pluginloader"
+	// External plugins — each registers EnvMutator(s) that run at workspace
+	// provision time. Loaded via soft-dep gates in main() so self-hosters
+	// without the App or without per-agent identity configured keep working.
+	githubappauth "github.com/Molecule-AI/molecule-ai-plugin-github-app-auth/pluginloader"
+	ghidentity "github.com/Molecule-AI/molecule-ai-plugin-gh-identity/pluginloader"
+
+	"github.com/Molecule-AI/molecule-monorepo/platform/pkg/provisionhook"
 )
 
 func main() {
@@ -153,22 +156,49 @@ func main() {
 		wh.SetCPProvisioner(cpProv)
 	}
 
+	// External-plugin env mutators — each plugin contributes 0+ mutators
+	// onto a shared registry. Order matters: gh-identity populates
+	// MOLECULE_AGENT_ROLE-derived attribution env vars that downstream
+	// mutators and the workspace's install.sh can then read. Keep
+	// github-app-auth last because it fails loudly on misconfig and its
+	// failure mode is "no GITHUB_TOKEN" — worth surfacing after the
+	// cheaper mutators already ran.
+	envReg := provisionhook.NewRegistry()
+
+	// gh-identity plugin — per-agent attribution via env injection + gh
+	// wrapper shipped as base64 env. Soft-dep: no config file is OK
+	// (plugin no-ops when no role is set on the workspace).
+	// Tracks molecule-core#1957.
+	if res, err := ghidentity.BuildRegistry(); err != nil {
+		log.Fatalf("gh-identity plugin: %v", err)
+	} else {
+		envReg.Register(res.Mutator)
+		log.Printf("gh-identity: registered (config file=%q)", os.Getenv("MOLECULE_GH_IDENTITY_CONFIG_FILE"))
+	}
+
 	// github-app-auth plugin — injects GITHUB_TOKEN + GH_TOKEN into every
 	// workspace env using the App's installation access token (rotates ~hourly).
 	// Soft-skip when GITHUB_APP_* env vars are absent so dev/self-hosters
 	// without an App configured keep working; fail-loud only on MISCONFIG
 	// (e.g. APP_ID set but key file missing), not on unset.
 	if os.Getenv("GITHUB_APP_ID") != "" {
-		if reg, err := pluginloader.BuildRegistry(); err != nil {
+		if reg, err := githubappauth.BuildRegistry(); err != nil {
 			log.Fatalf("github-app-auth plugin: %v", err)
 		} else {
-			wh.SetEnvMutators(reg)
-			log.Printf("github-app-auth: registered, %d mutator(s) in chain", reg.Len())
+			// Copy the plugin's mutators onto the shared registry so the
+			// TokenProvider probe (FirstTokenProvider) still finds them.
+			for _, m := range reg.Mutators() {
+				envReg.Register(m)
+			}
+			log.Printf("github-app-auth: registered, %d mutator(s) added to chain", reg.Len())
 		}
 	} else {
 		log.Println("github-app-auth: GITHUB_APP_ID unset — skipping plugin registration (agents will use any PAT from .env)")
 	}
 
+	wh.SetEnvMutators(envReg)
+	log.Printf("env-mutator chain: %v", envReg.Names())
+
 	// Offline handler: broadcast event + auto-restart the dead workspace
 	onWorkspaceOffline := func(innerCtx context.Context, workspaceID string) {
 		if err := broadcaster.RecordAndBroadcast(innerCtx, "WORKSPACE_OFFLINE", workspaceID, map[string]interface{}{}); err != nil {

workspace-server/go.mod

@@ -4,6 +4,7 @@ go 1.25.0
 
 require (
 	github.com/DATA-DOG/go-sqlmock v1.5.2
+	github.com/Molecule-AI/molecule-ai-plugin-gh-identity v0.0.0-20260424033845-4fd5ac7be30f
 	github.com/Molecule-AI/molecule-ai-plugin-github-app-auth v0.0.0-20260421064811-7d98ae51e31d
 	github.com/alicebob/miniredis/v2 v2.37.0
 	github.com/creack/pty v1.1.18

workspace-server/go.sum

@@ -4,6 +4,8 @@ github.com/DATA-DOG/go-sqlmock v1.5.2 h1:OcvFkGmslmlZibjAjaHm3L//6LiuBgolP7Oputl
 github.com/DATA-DOG/go-sqlmock v1.5.2/go.mod h1:88MAG/4G7SMwSE3CeA0ZKzrT5CiOU3OJ+JlNzwDqpNU=
 github.com/Microsoft/go-winio v0.4.21 h1:+6mVbXh4wPzUrl1COX9A+ZCvEpYsOBZ6/+kwDnvLyro=
 github.com/Microsoft/go-winio v0.4.21/go.mod h1:JPGBdM1cNvN/6ISo+n8V5iA4v8pBzdOpzfwIujj1a84=
+github.com/Molecule-AI/molecule-ai-plugin-gh-identity v0.0.0-20260424033845-4fd5ac7be30f h1:YkLRhUg+9qr9OV9N8dG1Hj0Ml7TThHlRwh5F//oUJVs=
+github.com/Molecule-AI/molecule-ai-plugin-gh-identity v0.0.0-20260424033845-4fd5ac7be30f/go.mod h1:NqdtlWZDJvpXNJRHnMkPhTKHdA1LZTNH+63TB66JSOU=
 github.com/Molecule-AI/molecule-ai-plugin-github-app-auth v0.0.0-20260421064811-7d98ae51e31d h1:GpYhP6FxaJZc1Ljy5/YJ9ZIVGvfOqZBmDolNr2S5x2g=
 github.com/Molecule-AI/molecule-ai-plugin-github-app-auth v0.0.0-20260421064811-7d98ae51e31d/go.mod h1:3a6LR/zd7FjR9ZwLTbytwYlWuCBsbCOVFlEg0WnoYiM=
 github.com/alicebob/miniredis/v2 v2.37.0 h1:RheObYW32G1aiJIj81XVt78ZHJpHonHLHW7OLIshq68=

workspace-server/internal/handlers/workspace_provision.go

@@ -96,6 +96,14 @@ func (h *WorkspaceHandler) provisionWorkspaceOpts(workspaceID, templatePath stri
 	applyAgentGitIdentity(envVars, payload.Name)
 	applyRuntimeModelEnv(envVars, payload.Runtime, payload.Model)
 
+	// Propagate the workspace's role into env so role-aware plugins
+	// (gh-identity — molecule-core#1957) can read it without the
+	// plugin interface having to carry the full payload. Role is
+	// cosmetic metadata — no auth weight on it — safe to surface as env.
+	if payload.Role != "" {
+		envVars["MOLECULE_AGENT_ROLE"] = payload.Role
+	}
+
 	// Plugin extension point: run any registered EnvMutators (e.g.
 	// github-app-auth, vault-secrets) AFTER built-in identity injection so
 	// plugins can override or augment GIT_AUTHOR_*, GITHUB_TOKEN, etc.
@@ -678,6 +686,11 @@ func (h *WorkspaceHandler) provisionWorkspaceCP(workspaceID, templatePath string
 
 	applyAgentGitIdentity(envVars, payload.Name)
 	applyRuntimeModelEnv(envVars, payload.Runtime, payload.Model)
+	// Propagate role for role-aware plugins (#1957). See provisionWorkspace
+	// above for rationale.
+	if payload.Role != "" {
+		envVars["MOLECULE_AGENT_ROLE"] = payload.Role
+	}
 	if err := h.envMutators.Run(ctx, workspaceID, envVars); err != nil {
 		log.Printf("CPProvisioner: env mutator failed for %s: %v", workspaceID, err)
 		// F1086 / #1206: env mutator errors (missing tokens, vault paths) must not

workspace-server/pkg/provisionhook/mutator.go

@@ -143,6 +143,21 @@ func (r *Registry) Names() []string {
 	return names
 }
 
+// Mutators returns a copy of the registered mutators in registration
+// order. Used when multiple plugins build their own registries and need
+// to merge onto a shared one at boot. Returns a copy so callers can't
+// mutate internal state.
+func (r *Registry) Mutators() []EnvMutator {
+	if r == nil {
+		return nil
+	}
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	out := make([]EnvMutator, len(r.mutators))
+	copy(out, r.mutators)
+	return out
+}
+
 // FirstTokenProvider returns the first registered mutator that also
 // implements TokenProvider, or nil if none do. Used to back the
 // GET /admin/github-installation-token endpoint so long-running