Shared Spinner component for button loading states

Adds a reusable shadcn-style Spinner (lucide loader-circle icon,
localized aria-label) and wires it into every button that has a
pending state: comment submit, delete, tag save, profile save,
admin saves, upload, login and register.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

package-lock.json

@@ -10,6 +10,7 @@
         "@dnd-kit/abstract": "^0.1.21",
         "@iconify-json/ph": "^1.2.2",
         "@iconify-json/simple-icons": "^1.2.98",
+        "@lucide/vue": "^1.51.0",
         "@nuxt/image": "^2.1.0",
         "@nuxtjs/i18n": "^10.6.0",
         "@tanstack/vue-table": "^9.2.4",
@@ -3575,6 +3576,15 @@
       "integrity": "sha512-GaHYm+c0O9MjZRu0ongGBRbinu8gVAMd2UZjji6jVmqKtZluZnptXGWhz1E8j8D2HJ3f/yMxKAUC0b+57wncIw==",
       "license": "MIT"
     },
+    "node_modules/@lucide/vue": {
+      "version": "1.51.0",
+      "resolved": "https://registry.npmjs.org/@lucide/vue/-/vue-1.51.0.tgz",
+      "integrity": "sha512-zMkTAMP8OsPESz/GDedsZfr3VUF2IiHlj25mBZG6Pc8A8J8BdygkE8k1HhRFXEUNzytp5DqxiBQNm3RG/U2bVg==",
+      "license": "ISC",
+      "peerDependencies": {
+        "vue": ">=3.0.1"
+      }
+    },
     "node_modules/@mapbox/jsonlint-lines-primitives": {
       "version": "2.0.3",
       "resolved": "https://registry.npmjs.org/@mapbox/jsonlint-lines-primitives/-/jsonlint-lines-primitives-2.0.3.tgz",