feat(launcher): script to replace launcher-only on legacy Gitea release

- gitea-replace-launcher-only.sh: swap Fractured-Launcher* + yml without wiping MPQs
- Only remove latest.yml / latest-linux.yml if a replacement exists in dist/
- README: bridge rollout steps and checklist item

Co-authored-by: Cursor <cursoragent@cursor.com>

tools/fractured-launcher-electron/README.md

@@ -115,6 +115,17 @@ CI workflow **Sync release to Gitea** (`.github/workflows/gitea-release-sync.yml
 
 **Manual upload:** `bash scripts/upload-release-to-gitea.sh /path/to/files v1.0.0` with the same env vars as CI.
 
+**Legacy “bridge” after changing `baked-gitea-channel.js`:** Players still using the old Gitea URL only receive launcher updates from that host. Build **Windows + Linux** installers (e.g. download **Fractured launcher CI** artifacts, or run **`npm run pack:win`** / **`npm run pack:linux`**), put **`dist/`** contents in one folder if needed, then:
+
+```bash
+export GITEA_BASE_URL=http://your-old-host:port   # legacy base, no trailing slash
+export GITEA_TOKEN=... GITEA_OWNER=Dawnsorrow GITEA_REPO=Fractured-Distro
+bash tools/fractured-launcher-electron/scripts/gitea-replace-launcher-only.sh \
+  tools/fractured-launcher-electron/dist latest
+```
+
+That script deletes only **`Fractured-Launcher*`**, **`latest.yml`** (only if you supply a new **`latest.yml`** in **`dist/`**), **`latest-linux.yml`** (only if supplied), **`*.blockmap`**, and **`builder-debug.yml`** on the release, then uploads the new files — **Wow.exe**, MPQs, and **`patch-manifest.json`** are left alone. If you only built Linux locally, merge **Windows CI `dist/`** files into the same folder first so **`latest.yml`** is not removed without a replacement. Use release tag **`latest`** if that is what **`release_tag`** points at.
+
 ### Sync did not run / Gitea unchanged — checklist
 
 1. **Git tag ≠ GitHub Release** — Only **Releases** (published on the GitHub **Releases** page) trigger this workflow. If your teammate only **`git push --tags`**, create a **Release** from that tag and click **Publish** (or run **Actions → Sync release to Gitea → Run workflow** and enter the tag).
@@ -130,6 +141,7 @@ CI workflow **Sync release to Gitea** (`.github/workflows/gitea-release-sync.yml
 11. **`EBUSY` / file locked on Windows** — The client (or antivirus) may keep **`.MPQ`** files open. The launcher **retries** for a short window and downloads the new file **before** replacing the old one; if sync still fails, **exit WoW** (and any tool previewing that folder) and run **Download updates** again.
 12. **`.bak-*` clutter** — When **Download updates** finishes without error, the launcher removes matching **`*.bak-YYYYMMDD-HHmmss`** files from earlier runs (same pattern it uses when replacing files). Failed syncs do not delete backups.
 13. **Gitea still shows an old launcher version** — The sync workflow overlays **`tools/fractured-launcher-electron` from the default branch**, so **`package.json`** there defines the built version. Ensure launcher changes are **merged to `main`** before publishing the GitHub release (or re-run **Actions → Sync release to Gitea** after merging). Previously, **Fractured-Launcher\*** files **attached on the GitHub release** were merged too, which could leave **two** installer versions on Gitea; those assets are now skipped in favor of CI-only builds.
+14. **Migrating `baked-gitea-channel.js` to a new host** — Publish **`gitea-replace-launcher-only.sh`** (see **Manual upload** above) on the **old** Gitea **`latest`** release so auto-update still works until clients move to the new URL.
 
 ### Private Gitea token for players