Implement KCA: web reimplementation of XCA PKI workflows

- kaya backend with OIDC sessions, API tokens, Postgres/Tortoise models
- AES-256-GCM private key storage and full certificate/CSR/CRL domain logic
- Sycamore/WASM SPA for vaults, keys, requests, certificates, CRLs and templates
- imports/exports, XCA .xdb migration, Docker Compose stack and tests

server/conftest.py

@@ -0,0 +1,12 @@
+"""pytest collection hook: mirror tests/__init__.py environment setup."""
+from __future__ import annotations
+
+import os
+
+os.environ.setdefault("DATABASE_URL", "sqlite://:memory:")
+os.environ.setdefault("OIDC_0_PROVIDER", "default")
+os.environ.setdefault("OIDC_0_ISSUER", "http://localhost:8180/kca")
+os.environ.setdefault("OIDC_0_CLIENT_ID", "kca")
+os.environ.setdefault("OIDC_0_REDIRECT_URI", "http://localhost:8080/auth/default/callback")
+os.environ.setdefault("KCA_MASTER_KEY", "MDEyMzQ1Njc4OWFiY2RlZjAxMjM0NTY3ODlhYmNkZWY=")
+os.environ.pop("REDIS_URL", None)