feat(server): podpuddle scaffold + Fastify backend (nostr auth, RSS, streams)

- docker-compose stack: podpuddle + MediaMTX (RTMP/WHIP/HLS) + blossom-server
- NIP-98 nostr-only login with session cookies, replay guard, clock-skew window
- podcasts/episodes CRUD; episodes register browser-uploaded blossom blobs
- RSS 2.0 + itunes + podcast namespace feeds with lnaddress value blocks
  (podcast:guid UUIDv5 verified against the spec vector)
- streams API with hashed stream keys; MediaMTX http-auth webhook
  (query/password/bearer forms); API poller flips live/ended status
- NIP-53 kind 30311 live events published with the server's nostr identity
- recordings: ffmpeg remux + server-key blossom upload → podcast episode
- 35 vitest tests green

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

server/package.json

@@ -0,0 +1,31 @@
+{
+  "name": "podpuddle-server",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "tsx watch src/index.ts",
+    "build": "tsc -p tsconfig.json",
+    "start": "node dist/index.js",
+    "test": "vitest run",
+    "typecheck": "tsc --noEmit"
+  },
+  "dependencies": {
+    "@fastify/cookie": "^11.0.2",
+    "@fastify/static": "^8.1.1",
+    "better-sqlite3": "^12.2.0",
+    "fastify": "^5.4.0",
+    "fastify-plugin": "^5.1.0",
+    "nostr-tools": "^2.15.0",
+    "ws": "^8.18.0",
+    "zod": "^3.25.0"
+  },
+  "devDependencies": {
+    "@types/better-sqlite3": "^7.6.13",
+    "@types/node": "^22.15.0",
+    "@types/ws": "^8.18.0",
+    "tsx": "^4.20.0",
+    "typescript": "^5.9.0",
+    "vitest": "^3.2.0"
+  }
+}