feat: enhance install script and theme generation

- install.sh now installs all variants when run without parameters
- preserve single-variant mode when --variant is specified
- add variant names to generated file headers for clarity
- fix tool name extraction to preserve compound names like git-delta
- fix CSS variable preservation during header generation

package.json

@@ -13,6 +13,7 @@
     "ci": "npm run lint && npm run generate && npm run validate && npm run test:e2e",
     "test": "npm run test:e2e",
     "test:e2e": "npx --yes playwright install --with-deps && playwright test",
+    "snapshots": "playwright test --update-snapshots",
     "demo": "python3 -m http.server 3000",
     "demo:open": "npm run demo & sleep 2 && open http://localhost:3000/docs/examples/web-demo.html",
     "install:themes": "./install.sh",