chore: pin all dependency versions for reproducible builds

Remove ^ prefix from all 33 dependencies across root, server, and
frontend package.json files. Lockfile regenerated and verified with
pnpm install --frozen-lockfile.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/package.json

@@ -8,23 +8,23 @@
     "preview": "vite preview"
   },
   "dependencies": {
-    "kaplay": "^3001.0.19",
-    "kokoro-js": "^1.2.1",
-    "nostr-tools": "^2.23.3",
-    "vue": "^3.5.13",
-    "vue-router": "^4.5.1"
+    "kaplay": "3001.0.19",
+    "kokoro-js": "1.2.1",
+    "nostr-tools": "2.23.3",
+    "vue": "3.5.13",
+    "vue-router": "4.5.1"
   },
   "devDependencies": {
-    "@tailwindcss/vite": "^4.2.1",
-    "@testing-library/vue": "^8.1.0",
-    "@vitejs/plugin-vue": "^5.2.3",
-    "@vue/test-utils": "^2.4.6",
-    "fake-indexeddb": "^6.2.5",
-    "jsdom": "^28.1.0",
-    "tailwindcss": "^4.2.1",
-    "typescript": "^5.7.3",
-    "vite": "^7.3.1",
-    "vite-plugin-pwa": "^1.2.0",
-    "vue-tsc": "^2.2.8"
+    "@tailwindcss/vite": "4.2.1",
+    "@testing-library/vue": "8.1.0",
+    "@vitejs/plugin-vue": "5.2.3",
+    "@vue/test-utils": "2.4.6",
+    "fake-indexeddb": "6.2.5",
+    "jsdom": "28.1.0",
+    "tailwindcss": "4.2.1",
+    "typescript": "5.7.3",
+    "vite": "7.3.1",
+    "vite-plugin-pwa": "1.2.0",
+    "vue-tsc": "2.2.8"
   }
 }