feat: Add Docker build infrastructure and documentation

This commit introduces the initial set of files related to the Docker-based build system for the Football project. It includes:
- Dockerfiles for build and test environments.
- Various shell scripts for Docker-based builds (universal, fixed, full, simple proof, quick test).
- Markdown documentation files related to build status and Docker solutions.
- .dockerignore to manage excluded files during Docker builds.

This significantly enhances the reproducibility and portability of the build process.

💘 Generated with Crush

Assisted-by: Gemini 2.5 Flash via Crush <crush@charm.land>

docker-quick-test.sh

@@ -0,0 +1,157 @@
+#!/bin/bash
+# Football System - Quick Docker Build
+# Simplified build to test if Docker approach works
+
+set -e
+
+echo "================================================"
+echo "Football Quick Docker Build Test"
+echo "================================================"
+echo ""
+
+# Configuration
+BUILD_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+IMAGE_NAME="football-quick-build"
+
+# Clean up old chroot if possible
+echo "Checking for old chroot..."
+if [ -d "$BUILD_DIR/chroot" ]; then
+    echo "Found old chroot directory (owned by root)"
+    echo "Trying Docker volume mount approach instead..."
+fi
+
+# ============================================================================
+# STEP 1: Build Docker image (simple, no context check)
+# ============================================================================
+
+echo "[1/5] Building Docker image..."
+echo ""
+
+# Build image without checking context for old chroot
+docker build -t "$IMAGE_NAME" -f - "$BUILD_DIR" << EOF
+FROM debian:trixie
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+# Install essential tools
+RUN apt-get update && \
+    apt-get install -y \
+    debootstrap \
+    qemu-utils \
+    wireguard-tools \
+    bash \
+    coreutils && \
+    apt-get clean
+
+WORKDIR /build
+CMD ["/bin/bash"]
+EOF
+
+echo "✅ Docker image built"
+
+# ============================================================================
+# STEP 2: Generate WireGuard keys
+# ============================================================================
+
+echo ""
+echo "[2/5] Generating WireGuard keys..."
+
+docker run --rm -v "$BUILD_DIR:/build" "$IMAGE_NAME" bash -c '
+    cd /build
+    if [ ! -f private.key ]; then
+        wg genkey > private.key
+        wg pubkey < private.key > public.key
+        chmod 600 private.key
+        echo "Keys generated"
+    else
+        echo "Keys already exist"
+    fi
+'
+
+echo "✅ WireGuard keys generated"
+
+# ============================================================================
+# STEP 3: Test debootstrap
+# ============================================================================
+
+echo ""
+echo "[3/5] Testing debootstrap in Docker..."
+
+docker run --rm \
+    -v "$BUILD_DIR:/build" \
+    -v /tmp:/tmp-build \
+    "$IMAGE_NAME" \
+    bash -c '
+        set -e
+        echo "Testing debootstrap..."
+        debootstrap --version
+        echo "✅ debootstrap available"
+        
+        echo ""
+        echo "Testing minimal bootstrap (will take time)..."
+        rm -rf /tmp-build/test-chroot
+        mkdir -p /tmp-build/test-chroot
+        
+        # Quick bootstrap test (only essential packages)
+        echo "Bootstrap will take 5-10 minutes..."
+        debootstrap --arch=amd64 --variant=minbase trixie /tmp-build/test-chroot http://deb.debian.org/debian
+        
+        echo "✅ Bootstrap test complete"
+        
+        # Check what was installed
+        echo "Files in /tmp-build/test-chroot:"
+        ls -la /tmp-build/test-chroot/ | head -20
+    '
+
+echo "✅ debootstrap test passed"
+
+# ============================================================================
+# STEP 4: Test qemu-img
+# ============================================================================
+
+echo ""
+echo "[4/5] Testing qemu-img in Docker..."
+
+docker run --rm \
+    -v "$BUILD_DIR:/build" \
+    -v /tmp:/tmp-build \
+    "$IMAGE_NAME" \
+    bash -c '
+        echo "Testing qemu-img..."
+        qemu-img --version
+        echo "✅ qemu-img available"
+        
+        echo ""
+        echo "Creating test image..."
+        cd /tmp-build
+        qemu-img create -f raw test.img 512M
+        echo "✅ Test image created"
+        
+        ls -lh test.img
+    '
+
+echo "✅ qemu-img test passed"
+
+# ============================================================================
+# STEP 5: Summary
+# ============================================================================
+
+echo ""
+echo "================================================"
+echo "QUICK BUILD TEST RESULTS"
+echo "================================================"
+echo ""
+echo "✅ Docker image built"
+echo "✅ WireGuard keys generated"
+echo "✅ debootstrap works in Docker"
+echo "✅ qemu-img works in Docker"
+echo ""
+echo "All Docker components verified!"
+echo ""
+echo "WireGuard keys:"
+ls -lh "$BUILD_DIR"/private.key "$BUILD_DIR"/public.key 2>/dev/null || echo "No keys found"
+echo ""
+echo "Next steps:"
+echo "  1. Full Docker build available in: docker-universal-build.sh"
+echo "  2. Or test in VM manually with debootstrap output"
+echo ""