Docs overhaul: beginner quick start + all-in-one NocoDB stack

- README rewritten around a copy-paste quick start (CLI and Portainer),
  verified alert test, day-to-day NocoDB operations, troubleshooting table, FAQ
- new docker-compose.allinone.yml: NocoDB (pinned 2026.09.0, SQLite) + monitor
  on a private network, with healthchecks and the Telegram IPv4 pin documented
- docs/: QUICKSTART-PORTAINER, TELEGRAM-SETUP, NOCODB-SETUP, ARCHITECTURE,
  OPERATIONS, TROUBLESHOOTING (replace DOCUMENTATION.md + COMPOSE-SETUP.md)
- secrets: SECRETS.md is gitignored and untracked; tracked template is
  SECRETS.example.md; real base id / chat id removed from .env.example
- LICENSE (MIT), .gitignore/.dockerignore tidied
- AGENTS.md: layout, iron rules, verification gates; host-specific deploy
  details moved to the gitignored OPS-INTERNAL.md

.gitignore

@@ -1,4 +1,11 @@
 .env
+.env.local
+SECRETS.md
+OPS-INTERNAL.md
 __pycache__/
 *.pyc
+*.pyo
 .DS_Store
+*.bak
+*.bak[0-9]
+_tmp_*