ci: publish famapp images to valhalla registry

Add Gitea Actions workflows (ci.yml, release.yml) that build and push
to registry.ginnoir.com. Disable GitHub release creation. Update all
doc/compose references from ghcr.io to registry.ginnoir.com.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.release-it.json

@@ -8,8 +8,7 @@
     "requireBranch": "main"
   },
   "github": {
-    "release": true,
-    "releaseName": "v${version}"
+    "release": false
   },
   "hooks": {
     "before:git:release": "echo 'Check: README.md reflects current modules and env vars before tagging'"