fix: ensure build dependencies and redirects for deployment

1. Move build-critical dependencies (`tailwindcss`, `postcss`, `autoprefixer`, etc.) to `dependencies` in `package.json` to prevent build failures in production environments (like Netlify) that prune `devDependencies`.
2. Ensure `_redirects` exists in the root directory (copied from `dist/_redirects`) so Netlify processes redirect rules correctly when publishing from root.

Co-authored-by: PR0M3TH3AN <[email protected]>

_redirects

@@ -0,0 +1 @@
+/* /index.html 200!

package.json

@@ -34,27 +34,27 @@
   "devDependencies": {
     "@noble/hashes": "^2.0.1",
     "@playwright/test": "^1.58.0",
-    "@tailwindcss/typography": "^0.5.15",
-    "autoprefixer": "^10.4.23",
     "cross-env": "^7.0.3",
-    "esbuild": "^0.25.12",
     "fake-indexeddb": "^6.2.5",
     "nostr-tools": "^2.19.4",
     "pixelmatch": "^5.3.0",
     "playwright": "^1.58.0",
     "pngjs": "^7.0.0",
-    "postcss": "^8.4.41",
     "prettier": "^3.8.1",
     "prettier-plugin-tailwindcss": "^0.6.5",
     "serve": "^14.2.5",
-    "stylelint": "^16.26.1",
-    "tailwindcss": "^3.4.19"
+    "stylelint": "^16.26.1"
   },
   "license": "GPL-3.0-or-later",
   "dependencies": {
     "@floating-ui/dom": "^1.7.4",
     "@noble/hashes": "^2.0.1",
+    "@tailwindcss/typography": "^0.5.15",
+    "autoprefixer": "^10.4.23",
+    "esbuild": "^0.25.12",
     "jsdom": "^27.4.0",
+    "postcss": "^8.4.41",
+    "tailwindcss": "^3.4.19",
     "ws": "^8.19.0"
   }
 }