H1 - Sanitize dev_docs/ for public release:
- Replace all real employee names with generic placeholders
(padak->admin1, matejkys->admin2, dasa->admin3, petr->john, etc.)
- Replace GCP project ID (kids-ai-data-analysis -> your-gcp-project)
- Replace server hostname (data-broker-for-claude -> your-server)
- Replace real IP address (34.88.8.46 -> YOUR_SERVER_IP)
- Replace internal FQDN with placeholder
- Covers: security.md, server.md, disaster-recovery.md, desktop-app.md,
session_explore.md, plan-rsync-fix.md, draft/*.md
H3 - webapp-setup.sh: validate sudoers syntax BEFORE copying to /etc/sudoers.d
- Prevents broken sudo if syntax is invalid
- Uses install -m 440 for atomic copy with correct permissions
M1 - setup.sh: deploy user created with /usr/sbin/nologin instead of /bin/bash
- CI/CD service account does not need interactive shell
M2 - config/loader.py: warn on missing env vars, validate webapp_secret_key
- _resolve_env_refs now logs warnings for unset ${ENV_VAR} references
- _validate_config checks auth.webapp_secret_key is non-empty
- Prevents Flask signing sessions with empty secret key
All 118 tests pass.