refactor: modular init, add bedrock loader, dynamic java/healthcheck

- Split monolithic init into modular lib files under scripts/lib/
  (common.sh, java.sh, server.sh, loaders/{vanilla,paper,fabric,forge,neoforge}.sh)
- Add bedrock loader: downloads from Minecraft Services API,
  runs native binary with LD_LIBRARY_PATH, skips Java setup
- Add auto-detection for JAVA_VERSION from Mojang version manifest
  (MC 1.20.5+ -> temurin@21, 1.17-1.20.4 -> temurin@17,
   1.17 -> temurin@16, pre-1.17 -> temurin@8)
- Fix NEW_FORGE unbound variable when non-Forge loaders run
- Fix Fabric loader jq filter (-s slurp removed, null string check fixed)
- Fix Forge test detection (recursive find for forge-*-server.jar)
- Dynamic healthcheck: nc -z TCP 25565 for Java, nc -zu UDP 19132 for bedrock
- Add .gitea/workflows/build-dev.yml for dev branch CI builds
- Base image: debian:bookworm-slim (from ubuntu:noble)
- Add unzip, netcat-openbsd to Docker image
- Switch to shebangs, set -euo pipefail throughout

compose.yaml

@@ -1,16 +1,43 @@
 services:
   dockercraft:
     image: git.jeremymcclure.com/jeremy/dockercraft:latest
+    # Use :dev to test builds from the dev branch
+    #image: git.jeremymcclure.com/jeremy/dockercraft:dev
     container_name: dockercraft
     stdin_open: true
     tty: true
     environment:
+      - EULA=true
       - MC_VERSION=1.21.1
 
-      - MC_LOADER=neoforge # paper, fabric, forge or neoforge
-      - MC_LOADER_VERSION=21.1.185
+      # Server loader type: paper, fabric, forge, neoforge, or bedrock
+      - MC_LOADER=neoforge
 
-      - JAVA_VERSION=temurin@21
+      # --- 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
+      - FORGE_VERSION=
+      - NEOFORGE_VERSION=21.1.185
+      - PAPER_BUILD=
+      #
+      # MC_LOADER_VERSION is a fallback for any loader that doesn't have
+      # its own var set. You usually don't need this.
+      - MC_LOADER_VERSION=
+      # -------------------------------------------------------------------
+
+      # For bedrock, MC_VERSION is the Bedrock server version (e.g. 1.21.50)
+      # and no Java is needed.
+      #
+      # --- Java Version --------------------------------------------------
+      # If unset, auto-detected from Mojang version manifest:
+      #   MC 1.20.5+ -> temurin@21, 1.17-1.20.4 -> temurin@17,
+      #   1.17 -> temurin@16, pre-1.17 -> temurin@8
+      # Set explicitly to pin a version. Uses Jabba
+      # (https://github.com/Jabba-Team/jabba) — supports temurin, zulu,
+      # adopt, openjdk, graalvm, and more.
+      #- JAVA_VERSION=temurin@21
+      # -------------------------------------------------------------------
       - JAR=server.jar
 
       - XMS=2G
@@ -25,7 +52,12 @@ services:
     volumes:
       - ./data:/data
     ports:
+      # Java (vanilla, paper, fabric, forge, neoforge): TCP 25565
+      # Bedrock: UDP 19132 (and UDP 19133 for IPv6)
+      # Expose the port matching your MC_LOADER:
       - 25565:25565
+      #- 19132:19132/udp
+      #- 19133:19133/udp
     deploy:
       resources:
         limits: