merge: preserve tested Copilot install sources 2960 and 2963

scripts/install-apply.js

@@ -39,6 +39,7 @@ Targets:
   cursor       - Install rules, hooks, and bundled Cursor configs to ./.cursor/
   antigravity  - Install rules, workflows, skills, and agents to ./.agents/
   codex        - Install shared agents/config into ~/.codex/
+  copilot      - Install skills and agents into ./.github/ for GitHub Copilot CLI (ECC hooks not configured)
   gemini       - Install project-local Gemini config into ./.gemini/
   opencode     - Install into OPENCODE_CONFIG_DIR, XDG_CONFIG_HOME/opencode, or ~/.config/opencode/
   codebuddy    - Install commands, agents, skills, and flattened rules into ./.codebuddy/

scripts/lib/harness-capabilities.js

@@ -114,6 +114,23 @@ const HARNESS_CAPABILITIES = deepFreeze([
     hooks: hooks('not-configured', false, 'ECC hooks are not configured by this adapter.'),
     aliases: ['google-antigravity'],
   },
+  {
+    id: 'copilot',
+    label: 'GitHub Copilot',
+    targetIds: ['copilot'],
+    channel: 'managed-project',
+    installMode: 'managed-project',
+    guidedReady: false,
+    availability: 'advanced',
+    destination: './.github',
+    scopes: [scope('project', 'copilot', './.github')],
+    hooks: hooks(
+      'not-configured',
+      false,
+      'ECC hooks target Claude Code events and are not installed for Copilot.'
+    ),
+    aliases: ['github-copilot', 'copilot-cli'],
+  },
   {
     id: 'gemini',
     label: 'Gemini CLI',

scripts/lib/install-lifecycle.js

@@ -42,6 +42,7 @@ const {
   validateManagedHooks,
 } = require('./install/claude-settings');
 const { adaptAntigravityAgent } = require('./install/antigravity-agent');
+const { adaptCopilotAgent } = require('./install/copilot-agent');
 const { buildInstallIndex, rewriteRelativeLinks } = require('./install/link-rewrite');
 const { getInstallTargetAdapter, listInstallTargetAdapters } = require('./install-targets/registry');
 const { resolveInvocationEnvironment } = require('./invocation-environment');
@@ -245,6 +246,9 @@ function transformCopyFileContent(operation, content) {
   if (operation.contentTransform === 'opencode-disable-plugin-entrypoint') {
     return getDisabledOpenCodePluginContent();
   }
+  if (operation.contentTransform === 'copilot-agent-frontmatter') {
+    return adaptCopilotAgent(content, operation.sourceRelativePath);
+  }
   throw new Error(`Unknown install content transform: ${operation.contentTransform}`);
 }
 
@@ -1919,9 +1923,11 @@ function prepareRepairMigration(plan, record) {
     statePreview: buildAdapterDerivedStatePreview(plan.statePreview, record),
   };
   const initialMigration = prepareClaudeSkillMigration(trustedPlan);
-  const guardedMigration = record.adapter.id === 'codex-home'
-    ? prepareUserOwnedFileGuard(trustedPlan, initialMigration)
-    : initialMigration;
+  // Repair normalizes recorded target metadata to the adapter-derived roots.
+  // Preserve its recorded operations as the ownership evidence.
+  const guardedMigration = prepareUserOwnedFileGuard(
+    trustedPlan, initialMigration, buildAdapterDerivedStatePreview(record.state, record)
+  );
   const migration = trustedPlan.target === 'opencode'
     ? require('./install/apply').prepareHookConsentMigration(trustedPlan, guardedMigration)
     : guardedMigration;
@@ -2240,9 +2246,7 @@ function repairInstalledStates(options = {}) {
             const { assertOpenCodeActivationUnchanged } = require('./install/apply');
             assertOpenCodeActivationUnchanged(desiredPlan, operation, activationSnapshot);
           }
-          if (record.adapter.id === 'codex-home') {
-            assertNoNewUserOwnedFile(migration, operation, desiredPlan);
-          }
+          assertNoNewUserOwnedFile(migration, operation, desiredPlan);
           const repairedPath = executeRepairOperation(
             context.repoRoot,
             operation,

scripts/lib/install-manifests.js

@@ -5,7 +5,7 @@ const { getInstallTargetAdapter, planInstallTargetScaffold } = require('./instal
 const { resolveInvocationEnvironment } = require('./invocation-environment');
 
 const DEFAULT_REPO_ROOT = path.join(__dirname, '../..');
-const SUPPORTED_INSTALL_TARGETS = ['claude', 'claude-project', 'cursor', 'antigravity', 'codex', 'gemini', 'opencode', 'codebuddy', 'joycode', 'qwen', 'zed', 'hermes', 'openclaw', 'kimi', 'adal'];
+const SUPPORTED_INSTALL_TARGETS = ['claude', 'claude-project', 'cursor', 'antigravity', 'codex', 'copilot', 'gemini', 'opencode', 'codebuddy', 'joycode', 'qwen', 'zed', 'hermes', 'openclaw', 'kimi', 'adal'];
 const COMPONENT_FAMILY_PREFIXES = {
   baseline: 'baseline:',
   language: 'lang:',

scripts/lib/install-targets/copilot-project.js

@@ -0,0 +1,97 @@
+const path = require('path');
+
+const {
+  createInstallTargetAdapter,
+  createManagedOperation,
+  createManagedScaffoldOperation,
+  normalizeRelativePath,
+} = require('./helpers');
+
+// GitHub Copilot CLI discovers skills from `.github/skills/` and custom agents
+// from `.github/agents/`. Those two directories are the entire supported
+// surface for this target: ECC's hooks target Claude Code's event model, and
+// commands rely on slash-command argument substitution Copilot does not
+// provide, so neither is installed here.
+const SUPPORTED_SOURCE_PREFIXES = ['agents', 'skills'];
+
+function hasPrefix(normalizedPath, prefix) {
+  return normalizedPath === prefix || normalizedPath.startsWith(`${prefix}/`);
+}
+
+function supportsCopilotSourcePath(sourceRelativePath) {
+  const normalizedPath = normalizeRelativePath(sourceRelativePath);
+  if (normalizedPath.split('/').includes('..')) return false;
+  return SUPPORTED_SOURCE_PREFIXES.some(prefix => hasPrefix(normalizedPath, prefix));
+}
+
+function stripPrefix(normalizedPath, prefix) {
+  return normalizedPath === prefix ? '' : normalizedPath.slice(`${prefix}/`.length);
+}
+
+function planSourcePathOperations(module, sourceRelativePath, targetRoot) {
+  const normalizedSourcePath = normalizeRelativePath(sourceRelativePath);
+
+  if (hasPrefix(normalizedSourcePath, 'agents')) {
+    return [
+      createManagedOperation({
+        moduleId: module.id,
+        sourceRelativePath: normalizedSourcePath,
+        destinationPath: path.join(
+          targetRoot,
+          'agents',
+          stripPrefix(normalizedSourcePath, 'agents')
+        ),
+        strategy: 'preserve-relative-path',
+        contentTransform: 'copilot-agent-frontmatter',
+      }),
+    ];
+  }
+
+  if (hasPrefix(normalizedSourcePath, 'skills')) {
+    return [
+      createManagedScaffoldOperation(
+        module.id,
+        normalizedSourcePath,
+        path.join(targetRoot, 'skills', stripPrefix(normalizedSourcePath, 'skills')),
+        'preserve-relative-path'
+      ),
+    ];
+  }
+
+  return [];
+}
+
+module.exports = createInstallTargetAdapter({
+  id: 'copilot-project',
+  target: 'copilot',
+  kind: 'project',
+  rootSegments: ['.github'],
+  installStatePathSegments: ['ecc-install-state.json'],
+  supportsModule(module) {
+    // Selection gating stays permissive so modules that only act as dependency
+    // anchors (rules-core, commands-core, platform-configs) still resolve.
+    // planOperations() is what narrows the install to agents and skills, so an
+    // unsupported path contributes zero operations rather than skipping the
+    // module and every module that depends on it.
+    const paths = Array.isArray(module && module.paths) ? module.paths : [];
+    return paths.length > 0;
+  },
+  planOperations(input, adapter) {
+    const modules = Array.isArray(input.modules)
+      ? input.modules
+      : (input.module ? [input.module] : []);
+    const { repoRoot, projectRoot, homeDir } = input;
+    const targetRoot = adapter.resolveRoot({ repoRoot, projectRoot, homeDir });
+
+    return modules.flatMap(module => {
+      const paths = Array.isArray(module.paths) ? module.paths : [];
+      return paths
+        .filter(supportsCopilotSourcePath)
+        .flatMap(sourceRelativePath => planSourcePathOperations(
+          module,
+          sourceRelativePath,
+          targetRoot
+        ));
+    });
+  },
+});

scripts/lib/install-targets/registry.js

@@ -4,6 +4,7 @@ const claudeHome = require('./claude-home');
 const claudeProject = require('./claude-project');
 const codebuddyProject = require('./codebuddy-project');
 const codexHome = require('./codex-home');
+const copilotProject = require('./copilot-project');
 const cursorProject = require('./cursor-project');
 const geminiProject = require('./gemini-project');
 const hermesHome = require('./hermes-home');
@@ -21,6 +22,7 @@ const ADAPTERS = Object.freeze([
   cursorProject,
   antigravityProject,
   codexHome,
+  copilotProject,
   geminiProject,
   hermesHome,
   opencodeHome,

scripts/lib/install/apply.js

@@ -52,6 +52,7 @@ const {
 } = require('./excluded-paths-reconciliation');
 const { buildInstallIndex, rewriteRelativeLinks } = require('./link-rewrite');
 const { adaptAntigravityAgent } = require('./antigravity-agent');
+const { adaptCopilotAgent } = require('./copilot-agent');
 
 function isMarkdownPath(filePath) {
   return /\.(md|mdx|markdown)$/i.test(String(filePath || ''));
@@ -70,6 +71,9 @@ function transformInstallContent(operation, content) {
   if (operation.contentTransform === 'opencode-disable-plugin-entrypoint') {
     return getDisabledOpenCodePluginContent();
   }
+  if (operation.contentTransform === 'copilot-agent-frontmatter') {
+    return adaptCopilotAgent(content, operation.sourceRelativePath);
+  }
   throw new Error(`Unknown install content transform: ${operation.contentTransform}`);
 }
 

scripts/lib/install/copilot-agent.js

@@ -0,0 +1,70 @@
+'use strict';
+
+// GitHub Copilot CLI custom agents are markdown files with `name` and
+// `description` frontmatter. Claude Code's agent files additionally carry
+// `model`, `tools`, and `color`, none of which transfer cleanly:
+//
+//   model  Copilot CLI resolves the session model from user configuration and
+//          plan entitlement. Carrying a Claude model id ("opus", "sonnet")
+//          makes Copilot emit "specifies model ... which is not available" on
+//          every invocation and silently fall back. Dropping the key selects
+//          the session default with no warning.
+//   tools  Claude tool names (Read, Grep, Bash, ...) are not Copilot CLI tool
+//          names. Copilot governs tool access at the session level through
+//          --allow-tool/--deny-tool, so carrying the Claude list would assert
+//          a restriction Copilot does not actually apply.
+//   color  Claude Code presentation only.
+//
+// The transform is therefore an allowlist rather than a denylist: unknown keys
+// added to ECC agents later cannot silently leak into the Copilot copy.
+const SUPPORTED_FRONTMATTER_KEYS = Object.freeze(['name', 'description']);
+
+const REQUIRED_FRONTMATTER_KEYS = Object.freeze(['name', 'description']);
+
+function splitFrontmatter(source, label) {
+  const match = String(source || '').match(/^---\r?\n([\s\S]*?)\r?\n---\r?\n/);
+  if (!match) {
+    throw new Error(`Cannot adapt Copilot agent ${label}: missing YAML frontmatter`);
+  }
+
+  // Keep YAML loading behind the transform boundary. Public help commands load
+  // the installer graph without executing a transform, including in hermetic
+  // packed-artifact checks where runtime dependencies are intentionally absent.
+  const frontmatter = require('js-yaml').load(match[1]);
+  if (!frontmatter || typeof frontmatter !== 'object' || Array.isArray(frontmatter)) {
+    throw new Error(`Cannot adapt Copilot agent ${label}: frontmatter must be an object`);
+  }
+
+  return {
+    frontmatter,
+    body: source.slice(match[0].length),
+  };
+}
+
+function adaptCopilotAgent(source, label = '<unknown>') {
+  const { frontmatter, body } = splitFrontmatter(source, label);
+
+  for (const key of REQUIRED_FRONTMATTER_KEYS) {
+    const value = frontmatter[key];
+    if (typeof value !== 'string' || value.trim() === '') {
+      throw new Error(`Cannot adapt Copilot agent ${label}: missing required frontmatter "${key}"`);
+    }
+  }
+
+  const adapted = {};
+  for (const key of SUPPORTED_FRONTMATTER_KEYS) {
+    if (Object.hasOwn(frontmatter, key)) {
+      adapted[key] = frontmatter[key];
+    }
+  }
+
+  const serialized = require('js-yaml')
+    .dump(adapted, { lineWidth: -1, noRefs: true })
+    .trimEnd();
+  return `---\n${serialized}\n---\n${body}`;
+}
+
+module.exports = {
+  adaptCopilotAgent,
+  SUPPORTED_FRONTMATTER_KEYS,
+};

scripts/lib/install/ownership-guard.js

@@ -37,10 +37,10 @@ function comparablePath(filePath) {
  *
  * All managed targets share this ownership boundary (#2964).
  */
-function prepareUserOwnedFileGuard(plan, migration) {
-  const previousState = pathExists(plan.installStatePath)
-    ? readInstallState(plan.installStatePath)
-    : null;
+function prepareUserOwnedFileGuard(plan, migration, recordedState) {
+  const previousState = recordedState === undefined
+    ? (pathExists(plan.installStatePath) ? readInstallState(plan.installStatePath) : null)
+    : recordedState;
   if (previousState && (
     previousState.target.id !== plan.adapter.id
     || comparablePath(previousState.target.root) !== comparablePath(plan.targetRoot)