Expose Forgejo publicly at forge.eblu.me (#278)

## Summary

Expose Forgejo publicly at `forge.eblu.me` via the Fly.io reverse proxy — the first dynamic, authenticated public-facing service.

- **Forgejo hardening:** Domain changed to forge.eblu.me, SSH stays on forge.ops.eblu.me, reverse proxy trust headers configured, local registration locked to external-only (Authentik SSO)
- **Tailscale Ingress:** ExternalName Service + Ingress in tailscale-operator creates forge.tail8d86e.ts.net endpoint
- **Fly.io proxy:** nginx server block with rate-limited auth endpoints (3r/s), fail2ban with custom nginx-deny action, security headers, /swagger blocked, WebSocket support, 512m body limit
- **Authentik:** OAuth callback updated to forge.eblu.me
- **DNS/TLS:** CNAME record in Pulumi, cert in fly-setup
- **Rename:** ~29 files updated from forge.ops.eblu.me to forge.eblu.me (HTTPS refs only; SSH, container builds, and Caddy table kept as-is)

## Deployment Order

1. `mise run provision-indri -- --tags forgejo` (config changes)
2. Verify forge.ops.eblu.me still works
3. `argocd app set tailscale-operator --revision feature/forge-public && argocd app sync tailscale-operator`
4. Verify `curl https://forge.tail8d86e.ts.net`
5. `cd fly && fly deploy`
6. Verify pre-DNS: `curl -H "Host: forge.eblu.me" https://blumeops-proxy.fly.dev/`
7. `fly certs add forge.eblu.me -a blumeops-proxy`
8. `argocd app set authentik --revision feature/forge-public && argocd app sync authentik`
9. `mise run dns-preview && mise run dns-up`
10. Full verification (see below)
11. Rehearse `mise run fly-shutoff`
12. After merge: reset ArgoCD revisions to main, re-sync

## Verification Checklist

- [ ] forge.eblu.me loads, shows public repos
- [ ] forge.ops.eblu.me still works from tailnet
- [ ] SSH clone via forge.ops.eblu.me:2222 works
- [ ] HTTPS clone via forge.eblu.me works
- [ ] UI shows forge.eblu.me for HTTPS clone, forge.ops.eblu.me for SSH
- [ ] /swagger returns 403
- [ ] Rapid login attempts trigger 429 rate limit
- [ ] fail2ban bans after 5 failed logins in 10 minutes
- [ ] ArgoCD can still sync (SSH unaffected)
- [ ] `mise run fly-shutoff` stops all public traffic
- [ ] `mise run services-check` passes

Reviewed-on: #278

ansible/playbooks/ringtail.yml

@@ -57,7 +57,7 @@
   tasks:
     - name: Ensure blumeops repo is present
       ansible.builtin.git:
-        repo: "https://forge.ops.eblu.me/eblume/blumeops.git"
+        repo: "https://forge.eblu.me/eblume/blumeops.git"
         dest: /etc/blumeops
         version: "{{ ringtail_commit | default('main') }}"
         force: true

ansible/roles/forgejo/defaults/main.yml

@@ -18,8 +18,8 @@ forgejo_log_path: "{{ forgejo_work_path }}/log"
 # Server settings
 forgejo_http_addr: 0.0.0.0
 forgejo_http_port: 3001
-forgejo_domain: forge.ops.eblu.me
-forgejo_ssh_domain: "{{ forgejo_domain }}"
+forgejo_domain: forge.eblu.me
+forgejo_ssh_domain: forge.ops.eblu.me
 forgejo_root_url: "https://{{ forgejo_domain }}/"
 forgejo_offline_mode: true
 

ansible/roles/forgejo/templates/app.ini.j2

@@ -20,6 +20,8 @@ SSH_LISTEN_PORT = {{ forgejo_ssh_listen_port }}
 LFS_START_SERVER = {{ forgejo_lfs_start_server | lower }}
 LFS_JWT_SECRET = {{ forgejo_lfs_jwt_secret }}
 OFFLINE_MODE = {{ forgejo_offline_mode | lower }}
+REVERSE_PROXY_LIMIT = 2
+REVERSE_PROXY_TRUSTED_PROXIES = *
 
 [database]
 DB_TYPE = {{ forgejo_db_type }}
@@ -40,7 +42,7 @@ ENABLED = false
 REGISTER_EMAIL_CONFIRM = false
 ENABLE_NOTIFY_MAIL = false
 DISABLE_REGISTRATION = {{ forgejo_disable_registration | lower }}
-ALLOW_ONLY_EXTERNAL_REGISTRATION = false
+ALLOW_ONLY_EXTERNAL_REGISTRATION = true
 ENABLE_CAPTCHA = false
 REQUIRE_SIGNIN_VIEW = {{ forgejo_require_signin_view | lower }}
 DEFAULT_KEEP_EMAIL_PRIVATE = false

ansible/roles/forgejo_actions_secrets/defaults/main.yml

@@ -4,7 +4,7 @@
 # This role syncs repository-level Actions secrets from 1Password to Forgejo
 # via the Forgejo API.
 
-forgejo_actions_secrets_api_url: "https://forge.ops.eblu.me/api/v1"
+forgejo_actions_secrets_api_url: "https://forge.eblu.me/api/v1"
 forgejo_actions_secrets_owner: eblume
 
 # Secrets to sync per repo.