Migrate skills to .agent/skills

.github/copilot-instructions.md

@@ -155,7 +155,7 @@ npm run lint:fix        # Auto-fix linting issues
 
 ## Storybook
 
-When working on UI components, always use the `primer-storybook` MCP tools to access Storybook's component and documentation knowledge before answering or taking any action. Reference the `.github/skills/storybook/SKILL.md` file for detailed instructions on using the Storybook MCP effectively and accurately.
+When working on UI components, always use the `primer-storybook` MCP tools to access Storybook's component and documentation knowledge before answering or taking any action. Reference the `.agent/skills/storybook/SKILL.md` file for detailed instructions on using the Storybook MCP effectively and accurately.
 
 **Story conventions:**
 
@@ -166,7 +166,7 @@ When working on UI components, always use the `primer-storybook` MCP tools to ac
 
 ## Slots
 
-When building, modifying, or wrapping compound components that use child-component "slots" (anything involving `__SLOT__`, `useSlots`, `isSlot`, or `asSlot`), reference the `.github/skills/slots/SKILL.md` file. It documents when to add slot markers, naming conventions for `Symbol(...)` descriptions, the public slot APIs, and common pitfalls.
+When building, modifying, or wrapping compound components that use child-component "slots" (anything involving `__SLOT__`, `useSlots`, `isSlot`, or `asSlot`), reference the `.agent/skills/slots/SKILL.md` file. It documents when to add slot markers, naming conventions for `Symbol(...)` descriptions, the public slot APIs, and common pitfalls.
 
 ## Known Issues and Workarounds
 
@@ -189,5 +189,5 @@ When building, modifying, or wrapping compound components that use child-compone
 When creating a pull request, you MUST:
 
 1. Use the template in `.github/pull_request_template.md` to structure the PR description. Read the template file, fill in all sections appropriately, and include it in the PR body.
-2. Include a changeset file in the PR if the change affects the published package (bug fix, new feature, breaking change, etc.). Create a `.changeset/<descriptive-name>.md` file with the appropriate semver bump type. Reference the `changesets` skill (`.github/skills/changesets/SKILL.md`) for detailed guidance on file format, choosing the correct bump type, and when a changeset can be skipped.
+2. Include a changeset file in the PR if the change affects the published package (bug fix, new feature, breaking change, etc.). Create a `.changeset/<descriptive-name>.md` file with the appropriate semver bump type. Reference the `changesets` skill (`.agent/skills/changesets/SKILL.md`) for detailed guidance on file format, choosing the correct bump type, and when a changeset can be skipped.
 3. If no changeset is needed (docs-only, test-only, CI/infra changes), add the `skip changeset` label to the pull request to bypass the CI changeset check.

.github/instructions/changesets.instructions.md

@@ -27,4 +27,4 @@ After adding, editing, or reverting changes in this PR, check the following:
 
 For changeset format, semver bump selection, when a changeset is not needed, and
 how to write terse descriptions, follow the `changesets` skill at
-`.github/skills/changesets/SKILL.md`.
+`.agent/skills/changesets/SKILL.md`.

.github/workflows/cleanup-feature-flags.md

@@ -62,7 +62,7 @@ merge a pull request, or change rollout behavior.
 
 ## Determine which flags are unused
 
-1. Read `.github/skills/feature-flags/SKILL.md`, the repository contribution
+1. Read `.agent/skills/feature-flags/SKILL.md`, the repository contribution
    instructions, and `packages/react/src/FeatureFlags/DefaultFeatureFlags.ts`.
    Also inventory flag-specific registrations in `packages/*/.storybook/`,
    including `featureFlagEnvList`, defaults, toolbar options, and decorators.
@@ -102,7 +102,7 @@ merge a pull request, or change rollout behavior.
   do not delete tests or snapshots merely to get a passing run. Remove a
   now-empty provider wrapper or unused import only when directly caused by
   this cleanup. Do not modify unrelated files, dependencies, or workflow files.
-- Follow `.github/skills/changesets/SKILL.md`: include a terse patch changeset
+- Follow `.agent/skills/changesets/SKILL.md`: include a terse patch changeset
   for `@primer/react` when changing its published default flag registry.
   Do not add a changeset for Storybook/test-only cleanup; request the
   `skip changeset` label in the PR description in that case.

package.json

@@ -26,7 +26,7 @@
     "lint:css": "stylelint --rd -q --cache '**/*.css'",
     "lint:css:fix": "npm run lint:css -- --fix",
     "lint:fix": "npm run lint -- --fix",
-    "lint:md": "markdownlint-cli2 \"**/*.{md,mdx}\" \"!.github\" \"!.changeset\" \"!.agents\" \"!**/node_modules/**\" \"!**/CHANGELOG.md\"",
+    "lint:md": "markdownlint-cli2 \"**/*.{md,mdx}\" \"!.github\" \"!.changeset\" \"!.agent\" \"!.agents\" \"!**/node_modules/**\" \"!**/CHANGELOG.md\"",
     "test": "vitest",
     "test:type-check": "tsc --noEmit",
     "test:update": "npm run test -- -u",