Replace tinycolor2 with colord (#36673)

[`colord`](https://github.com/omgovich/colord) is significantly smaller
than [`tinycolor2`](https://github.com/bgrins/TinyColor) (~4KB vs ~29KB
minified) and ships its own TypeScript types, removing the need for
`@types/tinycolor2`.

Behaviour is exactly the same for our use cases. By using `.alpha(1)` we
force the function to always output 6-digit hex format (it would output
8-digit for non-opaque colors).

---------

Signed-off-by: silverwind <me@silverwind.io>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -52,7 +52,7 @@
     "swagger-ui-dist": "5.31.1",
     "tailwindcss": "3.4.17",
     "throttle-debounce": "5.0.2",
-    "tinycolor2": "1.6.0",
+    "colord": "2.9.3",
     "tippy.js": "6.3.7",
     "toastify-js": "1.12.0",
     "tributejs": "5.1.3",
@@ -82,7 +82,6 @@
     "@types/sortablejs": "1.15.9",
     "@types/swagger-ui-dist": "3.30.6",
     "@types/throttle-debounce": "5.0.2",
-    "@types/tinycolor2": "1.4.6",
     "@types/toastify-js": "1.12.4",
     "@typescript-eslint/parser": "8.56.0",
     "@vitejs/plugin-vue": "6.0.4",