fix: migrate PaperMC to v3 API, fix NeoForge beta fallback, add test suite

- Migrate Paper loader from sunset v2 API to v3 (fill.papermc.io)
- Fix NeoForge: fall back to beta versions when no stable exists (set -e + grep)
- Fix setEula/setperms ordering (was writing eula.txt before /data was writable)
- Fix setEula/serverInfoWrite to use absolute paths (/data/server/)
- Add VOLUME directive removal (was shadowing bind mounts)
- Add comprehensive API test suite (110 tests across 6 suites)
- Move test.sh to tests/integration.sh, switch to named volumes
- Add Docker build cache to CI workflows
- Add .editorconfig, expand .gitignore, improve README docs

compose.yaml

@@ -16,9 +16,9 @@ services:
       # --- Loader versions -----------------------------------------------
       # Set the var matching your MC_LOADER above. Unset vars are ignored
       # for other loaders. Leave empty to auto-detect latest stable version.
-      - FABRIC_LOADER_VERSION=0.19.3
+      - FABRIC_LOADER_VERSION=
       - FORGE_VERSION=
-      - NEOFORGE_VERSION=21.1.185
+      - NEOFORGE_VERSION=
       - PAPER_BUILD=
       #
       # MC_LOADER_VERSION is a fallback for any loader that doesn't have
@@ -58,6 +58,19 @@ services:
       - 25565:25565
       #- 19132:19132/udp
       #- 19133:19133/udp
+    healthcheck:
+      test: >
+        bash -c '
+          if [ "${MC_LOADER}" = "bedrock" ]; then
+            nc -zu 127.0.0.1 19132;
+          else
+            nc -z 127.0.0.1 25565;
+          fi
+        '
+      start_period: 2m
+      interval: 30s
+      timeout: 10s
+      retries: 3
     deploy:
       resources:
         limits: