Initial commit: cert-manager API server

FastAPI-based SSL certificate automation server.
- Google Public CA wildcard cert issuance via certbot
- Cloudflare DNS-01 challenge with auto EAB key generation
- APISIX multi-instance deployment with domain-instance mapping
- Vault integration for all secrets
- Bearer token auth, retry logic, Discord DM alerts
- Auto-renewal scheduler (daily 03:00 UTC)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,27 @@
+FROM python:3.12-slim
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+        certbot \
+        python3-certbot-dns-cloudflare \
+        openssl \
+    && rm -rf /var/lib/apt/lists/*
+
+RUN pip install --no-cache-dir \
+    fastapi \
+    uvicorn[standard] \
+    httpx \
+    apscheduler \
+    pydantic \
+    google-auth \
+    requests \
+    tenacity
+
+WORKDIR /app
+COPY app/ /app/app/
+
+RUN mkdir -p /data/certbot/config /data/certbot/work /data/certbot/logs /data/config
+
+EXPOSE 8000
+
+CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000"]