### Summary
This PR refactors the playbook layout to reduce duplication and make host intent clearer (servers vs workstations), splits monitoring by host type, and restores full Zsh setup for developers while keeping servers aliases-only.
### Key changes
- **New playbooks**
- `playbooks/servers.yml`: baseline for server-class hosts (no desktop apps)
- `playbooks/workstations.yml`: baseline for dev/desktop/local + **desktop apps only on `desktop` group**
- **Monitoring split**
- `roles/monitoring_server`: server monitoring + intrusion prevention (includes `fail2ban`, sysstat)
- `roles/monitoring_desktop`: desktop-oriented monitoring tooling
- Updated playbooks to use the correct monitoring role per host type
- **Shell role: server-safe + developer-friendly**
- `roles/shell` now supports two modes:
- `shell_mode: minimal` (default): aliases-only, does not overwrite `.zshrc`
- `shell_mode: full`: installs Oh My Zsh + Powerlevel10k + plugins and deploys a managed `.zshrc`
- `playbooks/development.yml` and `playbooks/workstations.yml` use `shell_mode: full`
- `playbooks/servers.yml` remains **aliases-only**
- **Applications**
- Applications role runs only on `desktop` group (via `workstations.yml`)
- Removed Brave installs/repo management
- Added **CopyQ** to desktop apps (`applications_desktop_packages`)
- **Docs + architecture**
- Added canonical doc tree under `project-docs/` (overview/architecture/standards/workflow/decisions)
- Consolidated architecture docs: `docs/reference/architecture.md` is now a pointer to `project-docs/architecture.md`
- Fixed broken doc links by adding the missing referenced pages under `docs/`
### Behavior changes (important)
- Desktop GUI apps install **only** on the `desktop` inventory group (not on servers, not on dev VMs unless they are in `desktop`).
- Dev/workstation Zsh is now provisioned in **full mode** (managed `.zshrc` + p10k).
### How to test (local CI parity)
```bash
make test
npm test
```
Optional dry runs (interactive sudo may be required):
```bash
make check
make check-local
```
### Rollout guidance
- Apply to a single host first:
- Workstations: `make workstations HOST=<devhost>`
- Servers: `make servers HOST=<serverhost>`
- Then expand to group runs.
Reviewed-on: #4
- Introduce checks for existing GPG keys and repositories for Docker, NodeSource, and Tailscale to ensure correct configurations before installation.
- Implement conditional removal of incorrect keys and repositories to maintain a clean setup.
- Update Makefile to include a command for editing group vault variables.
These changes enhance package management reliability and streamline the installation process across different roles.
- Clean up duplicate Brave repository files in applications role.
- Ensure Ansible remote_tmp directory exists with correct permissions in base role.
- Remove existing NodeSource repository files and create keyrings directory in development role.
These changes improve package management and maintain a clean repository setup across roles.