feat: migrate from SDDM to greetd+tuigreet

- Add greetd role with tuigreet greeter (3 packages, 4.9MB)
- Replace SDDM as display-manager.service with greetd
- Add ADR 0003 documenting migration rationale
- Rename hyprland task: "register session in SDDM" -> "register
  Wayland session desktop entry"
- Add display_manager variables to vars/main.yml
- Add greetd role to workstation.yml
- Update setup.md timestamp

ansible/roles/greetd/handlers/main.yml

@@ -0,0 +1,4 @@
+---
+- name: restart greetd
+  command: systemctl restart greetd
+  become: yes

ansible/roles/greetd/tasks/main.yml

@@ -0,0 +1,28 @@
+---
+- name: Greetd - install packages
+  pacman:
+    name:
+      - "{{ display_manager_package }}"
+      - "{{ display_manager_greeter }}"
+    state: present
+    update_cache: yes
+  tags: [greetd, packages]
+
+- name: Greetd - configure tuigreet to launch Hyprland
+  template:
+    src: config.toml.j2
+    dest: "{{ display_manager_config }}"
+    owner: root
+    group: root
+    mode: '0644'
+  notify: restart greetd
+  tags: [greetd, config]
+
+- name: Greetd - ensure enabled as display manager
+  file:
+    src: /usr/lib/systemd/system/greetd.service
+    dest: /etc/systemd/system/display-manager.service
+    state: link
+    force: yes
+  notify: restart greetd
+  tags: [greetd, service]

ansible/roles/greetd/templates/config.toml.j2

@@ -0,0 +1,8 @@
+[terminal]
+# The VT to run the greeter on
+vt = 1
+
+# Default session: tuigreet greeter
+[default_session]
+command = "tuigreet --time --remember --asterisks --cmd {{ hyprland_cmd | default('Hyprland') }}"
+user = "greeter"

ansible/roles/hyprland/tasks/main.yml

@@ -44,7 +44,7 @@
   notify: rebuild initramfs
   tags: [hyprland, nvidia]
 
-- name: Hyprland - register session in SDDM
+- name: Hyprland - register Wayland session desktop entry
   copy:
     dest: /usr/share/wayland-sessions/hyprland.desktop
     content: |

ansible/vars/main.yml

@@ -65,3 +65,11 @@ hyprland_packages:
   - egl-wayland
   - qt5-wayland
   - qt6-wayland
+
+# ---------------------------------------------------------------------------
+# greetd role: display manager - minimal TUI greeter for Wayland
+# Replaced SDDM (2026-05-20) - see docs/adr/0003-sddm-to-greetd.md
+# ---------------------------------------------------------------------------
+display_manager_package: greetd
+display_manager_greeter: greetd-tuigreet
+display_manager_config: /etc/greetd/config.toml

ansible/workstation.yml

@@ -16,3 +16,5 @@
     - maintenance
     - role: hyprland
       tags: [hyprland]
+    - role: greetd
+      tags: [greetd]

docs/adr/0003-sddm-to-greetd.md

@@ -0,0 +1,95 @@
+---
+description: >-
+  Replace SDDM (Qt-based graphical display manager) with greetd + tuigreet
+  for a minimal, Wayland-first login experience with zero heavy GUI dependencies.
+status: accepted
+date: 2026-05-20
+replaces: SDDM as display-manager.service
+---
+
+# 0003: SDDM to greetd Migration
+
+## Context
+
+The workstation uses Hyprland as the primary Wayland compositor. SDDM was
+pulled in as the display manager with significant Qt dependencies (~50+
+transitive packages). For a single-user dev workstation running Hyprland,
+this is unnecessary overhead — heavy, slow-booting, and over-engineered for
+the use case.
+
+SDDM provides: graphical login prompt, session selection, PAM authentication.
+All three can be achieved with far lighter tools.
+
+## Decision
+
+Migrate from SDDM to greetd + tuigreet.
+
+- **greetd**: minimal display manager daemon, designed for Wayland first-class.
+- **tuigreet**: TUI greeter with time display, user remembering, session
+  discovery from `/usr/share/wayland-sessions/` and `/usr/share/xsessions/`.
+
+### What changed
+
+| Before | After |
+|--------|-------|
+| sddm.service (display-manager) | greetd.service (display-manager) |
+| Qt5/Qt6 dependency chain | greetd + greetd-tuigreet (3 packages, 4.9MB) |
+| /etc/sddm.conf | /etc/greetd/config.toml |
+| Graphical login screen | Text-based TUI login screen |
+| Heavy PAM surface | Standard PAM chain (system-local-login) |
+
+### Ansible changes
+
+- Added `greetd` role: installs packages, configures config.toml from template,
+  enables greetd as display-manager.service
+- Hyprland task renamed: "register session in SDDM" -> "register Wayland session
+  desktop entry" (no functional change, just accurate naming)
+- vars/main.yml: added `display_manager_package`, `display_manager_greeter`,
+  `display_manager_config` variables
+
+### Configuration
+
+```toml
+[terminal]
+vt = 1
+[default_session]
+command = "tuigreet --time --remember --asterisks --cmd Hyprland"
+user = "greeter"
+```
+
+### Rationale
+
+1. **Wayland-native**: greetd handles Wayland sessions cleanly without X
+   compatibility layers
+2. **Minimal**: 3 packages vs Qt dependency chain; <5MB vs ~500MB
+3. **Maintained**: Rust codebase, clean TOML config, Arch repos (no AUR)
+4. **AI-agent friendly**: TOML config is trivially parseable/modifiable;
+   clean systemd service with structured journalctl output
+5. **Simplicity principle**: maximizes work not done
+
+## Consequences
+
+### Positive
+
+- Faster boot (no Qt/Xorg init)
+- Smaller attack surface
+- Less disk usage
+- No Qt dependencies to maintain
+- Clean systemd service management
+
+### Negative
+
+- No graphical login (only a limitation if multi-user GUI switching is needed)
+- SDDM themes not available (not a requirement for this workstation)
+- Tuigreet has fewer visual customization options
+
+### Migration path back
+
+```bash
+sudo systemctl disable greetd
+sudo systemctl enable sddm
+sudo ln -sf /usr/lib/systemd/system/sddm.service /etc/systemd/system/display-manager.service
+```
+
+Reversible with zero data loss — the hyprland.desktop session entry is
+unchanged and works with both DMs.

docs/tech/setup.md

@@ -5,7 +5,7 @@ tags:
   - setup
   - bootstrap
   - ansible
-last_updated: '2026-05-18'
+last_updated: '2026-05-20'
 ---
 
 # Workstation Setup Guide