chore: remove obsolete DEVELOPMENT.md and consolidate task tracking docs

.github/MEMORY.md

@@ -122,3 +122,15 @@
   - Frontend: 45 tests pass (2 files), test:coverage meets thresholds (22.92% / 18.44% / 19.01% / 25.42%)
 - Edge cache validation script `scripts/validate-edge-cache.sh` exists.
 - Remaining: CORS on media.linearvoid.tv (Cloudflare R2 bucket CORS config, not a code change). Phases 5-7 are manual/infrastructure only (Cloudflare dashboard, Hetzner provisioning, live benchmarks).
+
+## 2026-08-11
+
+- Consolidated all development tasks from `DEVELOPMENT.md` and `.github/instructions/TODO.md` into `.github/instructions/BACKLOG.md` as the single source of truth. `DEVELOPMENT.md` now obsolete and removed. `TODO.md` references `BACKLOG.md` and `DONE.md`.
+- Fixed R2 endpoint validation in playout service (`backend/playout/src/playlist.go`):
+  - Added `isR2Configured()` checking all four required env vars (`R2_ENDPOINT`, `R2_ACCESS_KEY_ID`, `R2_SECRET_ACCESS_KEY`, `R2_BUCKET_NAME`).
+  - `initR2Client()` now returns a clear error if R2 is not configured instead of creating an S3 client with an empty endpoint.
+  - Segment watcher (`watchAndPublishSegments`), `syncLatestToR2()`, and `publishManifest()` are now guarded by `r2Client != nil` — no error spam when R2 is unavailable.
+  - Playout gracefully degrades: local HLS via nginx works without R2.
+- Updated `.gitea/workflows/cd.yml` "Prepare environment" step to include all R2* variables sourced from Gitea secrets (`R2_ACCESS_KEY_ID`, `R2_SECRET_ACCESS_KEY`, `R2_BUCKET_NAME`, `R2_ENDPOINT`, `R2_ADMIN*\*`), Cloudflare variables (`CLOUDFLARE_API_TOKEN`, `CLOUDFLARE_ACCOUNT_ID`), and frontend public URL variables.
+- Updated `docs/DEPLOYMENT.md` "Environment File" section: replaced vague "Cloudflare/R2 variables" bullet with explicit variable lists and added a new "Gitea Secrets" table documenting all 15 required secrets.
+- All playout tests pass (20 tests), `go vet` clean.