Migration: consolidate Echo6 docs to cortex with full infrastructure cleanup sync

- Documents recent infrastructure cleanup (8 CTs destroyed, 35 DNS records removed, Headscale cleanup)
- Adds 24 new runbooks covering Authentik, PeerTube, Meshtastic, RECON, Proxmox, Mailcow, Internet Archive, GPU routing
- Adds project documentation for headscale, vaultwarden, peertube, matrix, mmud, advbbs, arr stack
- Updates services.md, environment.md, caddy.md, authentik.md to match live infrastructure
- Removes 4 deprecated runbook duplicates (canonical versions live in projects/)
- Adds .gitignore for binary archives and editor temp files

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

appservices.ref

@@ -0,0 +1,13 @@
+# Appservices Reference
+# Generated: 2026-04-09 (Phase 1)
+
+## Current Appservices: NONE
+
+No appservices are currently registered with Synapse.
+- No app_service_config_files key in homeserver.yaml
+- No registration YAML files in /opt/matrix/synapse/
+- No ports in the 29xxx range are in use
+
+## Available Port Range
+- 29328 (mautrix-signal default) — AVAILABLE
+- Full 29000-29999 range — AVAILABLE (confirmed via ss -tlnp)