feat: Add Docker infrastructure with Caddy and startup scripts (#25, #26)

Issue #25 - Docker multi-service infrastructure:
- Create docker/Dockerfile with multi-stage build, git support, port 8080
- Create docker/docker-compose.yml with app + Caddy services
- Create docker/Caddyfile for HTTPS termination and reverse proxy
- Create docker/.env.example with configuration template

Issue #26 - Startup scripts and tests:
- Create scripts/start.sh for production startup with env validation
- Create scripts/healthcheck.sh for Docker health checks
- Add health endpoint tests to test_mcp_endpoints.py
- Fix middleware order (HealthCheckBypass must wrap BearerAuth)
- Fix pyproject.toml testpaths to use 'tests' directory
- Update test_config.py for new defaults (0.0.0.0:8080)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

scripts/healthcheck.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+# Health check script for Gitea MCP Remote
+#
+# Used by Docker healthcheck and monitoring systems.
+# Returns exit code 0 if healthy, 1 if unhealthy.
+
+set -e
+
+HOST="${HTTP_HOST:-localhost}"
+PORT="${HTTP_PORT:-8080}"
+ENDPOINT="http://${HOST}:${PORT}/health"
+
+# Make request and check response
+response=$(curl -sf "$ENDPOINT" 2>/dev/null) || exit 1
+
+# Verify JSON response contains status: ok
+if echo "$response" | grep -q '"status".*"ok"'; then
+    exit 0
+else
+    exit 1
+fi