feat(ops): replace Cloudflare Pages with Workers for frontend hosting

.github/MEMORY.md

@@ -109,7 +109,7 @@
   - Total: 45 frontend tests passing (2 test files).
 - Added coverage reporting: `vitest.config.ts` with v8 provider, thresholds at 20/15/15/20 (statements/branches/functions/lines).
 - Added `test:coverage` script to `package.json`.
-- Fixed CI: bumped Node from 20 to 22 in `ci.yml` and `pages-deploy.yml` (jsdom@30 requires Node 22+). Added `engines` to `package.json`.
+- Fixed CI: bumped Node from 20 to 22 in `ci.yml` and `workers-deploy.yml` (jsdom@30 requires Node 22+). Added `engines` to `package.json`.
 - Updated AGENTS.md: added Required tracking files table with 13 docs and update cadence.
 - All Go vet, Go tests, frontend test:coverage passing.
 - CORS on media.linearvoid.tv remains the only streaming pipeline gap (Cloudflare R2 config, not code).

.github/instructions/BACKLOG.md

@@ -6,8 +6,8 @@
 
 ### Phase 5: complete manual Cloudflare and external-service setup
 
-- [ ] Apply Cloudflare Pages, Tiered Cache, WAF, rate limiting, and HTTPS/HSTS settings in the dashboard
-- [ ] Cloudflare Pages: link custom domain and cut over frontend hosting
+- [ ] Apply Cloudflare Workers, Tiered Cache, WAF, rate limiting, and HTTPS/HSTS settings in the dashboard
+- [ ] Cloudflare Workers: link custom domain and cut over frontend hosting
 - [ ] Enable Smart Tiered Cache; validate `Cf-Cache-Status: HIT` from upper tier
 - [ ] WAF: enable OWASP Managed Ruleset (Simulate → review 48h → Block), enable Bot Fight Mode
 - [ ] Rate limiting: `/api/admin/login` + `/api/admin/*` → 10 req/10s per IP, Challenge action
@@ -58,10 +58,10 @@
 
 ## Cloudflare Configuration
 
-### DNS & Pages
+### DNS & Workers
 
-- [ ] Cloudflare Pages: link custom domain (manual)
-- [ ] Create Cloudflare Pages project and cut over frontend hosting (manual)
+- [ ] Cloudflare Workers: link custom domain (manual)
+- [ ] Create Cloudflare Worker and cut over frontend hosting (manual)
 
 ### Security & TLS