replace NPM with vanilla nginx + certbot

- nginx:alpine replaces nginx-proxy-manager
- certbot on host with standalone issuance and auto-renewal
- per-site nginx configs in conf.d/ (HTTP->HTTPS, bare->www)
- container names use underscores (timothykim_net)
- setup.sh: automated cert issuance, dynamic app startup
- deploy.sh: nginx -t guard, graceful image-not-found
- new-app.sh: Gitea API repo creation, nginx conf generation
- add ARCHITECTURE.md, USECASES.md, CLAUDE.md
- remove old NPM data/certs from tracking

docker/timothykim.net/compose.yml

@@ -2,7 +2,7 @@ services:
   static:
     image: git.timothykim.net/hantim/static:latest
     restart: unless-stopped
-    container_name: timothykim-static
+    container_name: timothykim_net
     networks:
       - shared