add Gitea Bot interface: webhook server, API tool, Caddy ingress

- Add src/gitea.rs: axum webhook server on :9800, handles @mention in
  issues and PRs, spawns claude -p for review, posts result as comment
- Add call_gitea_api tool: LLM can directly call Gitea REST API with
  pre-configured admin token (noc_bot identity)
- Add Caddy to Docker image as ingress layer (subdomain/path routing)
- Config: add gitea section with token_file support for auto-provisioned token
- Update suite.md: VPS-first deployment, SubAgent architecture, Caddy role

Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 
 [dependencies]
 anyhow = "1"
+axum = "0.8"
 base64 = "0.22"
 chrono = { version = "0.4", features = ["serde"] }
 cron = "0.16"