feat(docs): move the site to prdcs.wiki on a Cloudflare Worker

Blume's cloudflare() adapter builds the docs as the prdcs-wiki Worker
(apps/docs/wrangler.jsonc: name, prdcs.wiki custom domain), and deploy.yml
ships it with wrangler instead of GitHub Pages. The SRS Worker's DOCS_URL /
DOCS_ORIGIN, release links and README badge follow the new domain.

apps/api/wrangler.jsonc

@@ -32,8 +32,8 @@
     "REPO": "prdlk/leetcode",
     "FROM_EMAIL": "srs@prdlk.com",
     "TO_EMAIL": "prnk28@gmail.com",
-    "DOCS_URL": "https://lc.prd.lk",
-    "DOCS_ORIGIN": "https://lc.prd.lk,https://prdlk.github.io",
+    "DOCS_URL": "https://prdcs.wiki",
+    "DOCS_ORIGIN": "https://prdcs.wiki",
     "PUBLIC_URL": "https://srs-api.prdlk.workers.dev",
     // The docs assistant's OpenRouter model (POST /ask). `:free` variants share
     // an upstream pool and answer 429 when it is saturated.