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

README.md

@@ -1 +1,62 @@
-TODO
+# Dockercraft
+
+A Docker image for running Minecraft servers with support for multiple loaders.
+
+## Usage
+
+```yaml
+services:
+  minecraft:
+    image: git.jeremymcclure.com/jeremy/dockercraft:latest
+    container_name: minecraft
+    stdin_open: true
+    tty: true
+    environment:
+      - EULA=true
+      - MC_VERSION=1.21.1
+      - MC_LOADER=neoforge
+      - MC_LOADER_VERSION=21.1.185
+      - JAVA_VERSION=temurin@21
+      - XMS=2G
+      - XMX=4G
+      - PUID=1000
+      - PGID=1000
+    volumes:
+      - ./data:/data
+    ports:
+      - 25565:25565
+    restart: unless-stopped
+```
+
+## Environment Variables
+
+| Variable | Default | Description |
+|---|---|---|
+| `EULA` | — | **Required.** Set to `true` to accept the Minecraft EULA |
+| `MC_VERSION` | — | Minecraft version (e.g., `1.21.1`) |
+| `MC_LOADER` | — | Server loader: `vanilla`, `paper`, `fabric`, `forge`, or `neoforge` |
+| `MC_LOADER_VERSION` | — | Fallback version for any loader |
+| `FABRIC_LOADER_VERSION` | `$MC_LOADER_VERSION` | Fabric loader version |
+| `FORGE_VERSION` | `$MC_LOADER_VERSION` | Forge version (e.g., `52.1.14`) |
+| `NEOFORGE_VERSION` | `$MC_LOADER_VERSION` | NeoForge version (e.g., `21.1.185`) |
+| `PAPER_BUILD` | latest | Paper build number (auto-detects latest if unset) |
+| `JAVA_VERSION` | auto-detected | Java version (via Jabba, e.g., `temurin@21`, `zulu@17`). Auto-detects from Mojang manifest if unset: 1.20.5+→21, 1.17-1.20.4→17, 1.17→16, pre-1.17→8 |
+| `JAR` | `server.jar` | Server jar filename |
+| `XMS` | `2G` | Initial Java heap size |
+| `XMX` | `4G` | Maximum Java heap size |
+| `ADD_ARGS` | — | Additional Java arguments |
+| `PUID` | `1000` | User ID for /data ownership |
+| `PGID` | `1000` | Group ID for /data ownership |
+
+## Supported Loaders
+
+- **Vanilla** — Official Mojang server
+- **Paper** — High-performance papermc.io
+- **Fabric** — Lightweight mod loader via fabricmc.net
+- **Forge** — Heavyweight mod loader via minecraftforge.net
+- **NeoForge** — Fork of Forge via neoforged.net
+- **Bedrock** — Official Bedrock dedicated server (native binary, no Java required)
+
+## Volumes
+
+- `/data` — Persists server data, worlds, config, and Java installations