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

scripts/lib/loaders/fabric.sh

@@ -1,22 +1,33 @@
 getFabric() {
   SERVER_TYPE="Fabric Minecraft"
-  LATEST_BUILD=$(curl -s https://meta.fabricmc.net/v2/versions/loader/${MC_VERSION} | jq -r '.[0].loader.version')
-  LATEST_INSTALLER=$(curl -s https://maven.fabricmc.net/net/fabricmc/fabric-installer/maven-metadata.xml | xmllint --xpath "/metadata/versioning/latest/text()" -)
 
-  if [[ -z "$MC_VERSION" ]]; then
-    echo "Minecraft version not set"
-    exit 1
+  if [[ -z "${MC_VERSION}" ]]; then
+    die "MC_VERSION is required for Fabric loader"
   fi
-  VER=$MC_VERSION
 
+  log "Fetching Fabric loader version for MC ${MC_VERSION}..."
+  local LATEST_BUILD LATEST_INSTALLER
+  LATEST_BUILD=$(curl -sf --connect-timeout 10 --max-time 30 \
+    "https://meta.fabricmc.net/v2/versions/loader/${MC_VERSION}" |
+    jq -r '.[0].loader.version')
+
+  LATEST_INSTALLER=$(curl -sf --connect-timeout 10 --max-time 30 \
+    "https://maven.fabricmc.net/net/fabricmc/fabric-installer/maven-metadata.xml" |
+    xmllint --xpath "/metadata/versioning/latest/text()" -)
+
+  if [[ -z "$LATEST_BUILD" || "$LATEST_BUILD" == "null" ]]; then
+    die "No Fabric loader found for MC ${MC_VERSION}"
+  fi
+  if [[ -z "$LATEST_INSTALLER" ]]; then
+    die "Could not determine latest Fabric installer version"
+  fi
+
+  local VER_LOADER
   VER_LOADER="${FABRIC_LOADER_VERSION:-${LATEST_BUILD}}"
-  DL_URL=https://meta.fabricmc.net/v2/versions/loader/${MC_VERSION}/${VER_LOADER}/${LATEST_INSTALLER}/server/jar
+  local DL_URL
+  DL_URL="https://meta.fabricmc.net/v2/versions/loader/${MC_VERSION}/${VER_LOADER}/${LATEST_INSTALLER}/server/jar"
 
-  if [ "$LATEST_BUILD" != "null" ]; then
-    echo "$DL_URL"
-    curl -o server.jar "${DL_URL}"
-  else
-    echo "No valid Fabric build found for version ${MC_VERSION}"
-    crash
-  fi
+  log "Downloading Fabric (loader ${VER_LOADER}, installer ${LATEST_INSTALLER})..."
+  curl -fL -o server.jar "${DL_URL}"
+  log "Fabric ${MC_VERSION} (loader ${VER_LOADER}) downloaded."
 }