feat(metadata|docs): reusable tag groups with $group: (#5037)

* feat(metadata): reusable tag groups with `$group:`

A `$group:<group-name>` marker in `tags` is replaced in place with the tags of
`groups/<group-name>.json`: a small set of tags for what a variant suffix
means, such as `-minus` → remove, delete.

- Read groups in `readGroups` and resolve markers next to `$extends:`,
  failing on unknown groups and on `$group:` outside `tags`
- Add `group.schema.json` and lint, spell-check and format `groups/*.json`
- `pnpm checkIcons` also fails on literals a group already provides, and
  warns about icons that list a group's tags by hand and unused groups
- Add the `minus`, `plus` and `x` groups and use them in
  `alarm-clock-minus`, `file-minus`, `file-plus` and `file-x`

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Fix group checker

* Apply batched suggestions from code review

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

* feat(metadata): reusable tag groups with `$group:`

A `$group:<group-name>` marker in `tags` is replaced in place with the tags of
`groups/<group-name>.json`: a small set of tags for what a variant suffix
means, such as `-minus` → remove, delete.

- Read groups in `readGroups` and resolve markers next to `$extends:`,
  failing on unknown groups and on `$group:` outside `tags`
- Add `group.schema.json` and lint, spell-check and format `groups/*.json`
- `pnpm checkIcons` also fails on literals a group already provides, and
  warns about icons that list a group's tags by hand and unused groups
- Add the `minus`, `plus` and `x` groups and use them in
  `alarm-clock-minus`, `file-minus`, `file-plus` and `file-x`

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Fix group checker

* Apply batched suggestions from code review

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

* feat(metadata): reusable tag groups with `$group:`

A `$group:<group-name>` marker in `tags` is replaced in place with the tags of
`groups/<group-name>.json`: a small set of tags for what a variant suffix
means, such as `-minus` → remove, delete.

- Read groups in `readGroups` and resolve markers next to `$extends:`,
  failing on unknown groups and on `$group:` outside `tags`
- Add `group.schema.json` and lint, spell-check and format `groups/*.json`
- `pnpm checkIcons` also fails on literals a group already provides, and
  warns about icons that list a group's tags by hand and unused groups
- Add the `minus`, `plus` and `x` groups and use them in
  `alarm-clock-minus`, `file-minus`, `file-plus` and `file-x`

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Fix group checker

* Apply batched suggestions from code review

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

* feat(metadata): reusable tag groups with `$group:`

A `$group:<group-name>` marker in `tags` is replaced in place with the tags of
`groups/<group-name>.json`: a small set of tags for what a variant suffix
means, such as `-minus` → remove, delete.

- Read groups in `readGroups` and resolve markers next to `$extends:`,
  failing on unknown groups and on `$group:` outside `tags`
- Add `group.schema.json` and lint, spell-check and format `groups/*.json`
- `pnpm checkIcons` also fails on literals a group already provides, and
  warns about icons that list a group's tags by hand and unused groups
- Add the `minus`, `plus` and `x` groups and use them in
  `alarm-clock-minus`, `file-minus`, `file-plus` and `file-x`

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Fix group checker

* Apply batched suggestions from code review

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

package.json

@@ -36,7 +36,7 @@
     "suggest:metadata:debug": "pnpm --filter @lucide/suggest-metadata-action debug",
     "suggest:metadata:watch": "pnpm --filter @lucide/suggest-metadata-action watch",
     "postinstall": "husky",
-    "lint:es": "eslint . --ignore-pattern 'icons/*.json' --ignore-pattern 'categories/*.json'",
+    "lint:es": "eslint . --ignore-pattern 'icons/*.json' --ignore-pattern 'categories/*.json' --ignore-pattern 'groups/*.json'",
     "lint:format": "prettier \"**/*.{js,mjs,ts,jsx,tsx,html,css,scss,json,yml,yaml}\" --check",
     "lint:format-fix": "prettier \"**/*.{js,mjs,ts,jsx,tsx,html,css,scss,json,yml,yaml}\" --write",
     "lint:icons": "prettier \"icons/*.svg\" --check",
@@ -44,8 +44,9 @@
     "lint:format:ci": "node ./scripts/lintFormat.mts",
     "lint:json:icons": "eslint 'icons/*.json'",
     "lint:json:categories": "eslint 'categories/*.json'",
-    "lint:json": "eslint 'icons/*.json' 'categories/*.json'",
-    "lint:spelling": "cspell --no-progress 'icons/*.json' 'categories/*.json'",
+    "lint:json:groups": "eslint 'groups/*.json'",
+    "lint:json": "eslint 'icons/*.json' 'categories/*.json' 'groups/*.json'",
+    "lint:spelling": "cspell --no-progress 'icons/*.json' 'categories/*.json' 'groups/*.json'",
     "lint:spelling:ci": "node ./scripts/lintSpelling.mts",
     "lint:icons:all": "pnpm run lint:icons && pnpm run lint:json:icons",
     "lint": "pnpm lint:es && pnpm lint:format && pnpm lint:json && pnpm lint:spelling && pnpm lint:icons",