feat: add Nemo file manager as default (Ubuntu + Fedora)

Install Nemo alongside Nautilus and set as default file manager:
- Nemo is Linux Mint's fork of Nautilus with more features
- Dual-pane mode (F3), tree view, better bulk rename, plugins
- Nautilus remains installed for GNOME integration
- xdg-mime sets Nemo as default for inode/directory

Packages installed:
- Ubuntu: nemo, nemo-fileroller (from universe, no PPA needed)
- Fedora: nemo, nemo-fileroller, nemo-preview

Author: Derek

ansible/roles/dfe_developer/tasks/main.yml

@@ -15,6 +15,16 @@
   tags: ['desktop']
   when: ansible_facts['distribution'] in ['Fedora', 'Ubuntu']
 
+- name: Install Nemo file manager (replaces Nautilus as default)
+  ansible.builtin.include_tasks:
+    file: nemo.yml
+    apply:
+      tags: ['nemo', 'desktop']
+  tags: ['nemo', 'desktop']
+  when:
+    - ansible_facts['distribution'] in ['Fedora', 'Ubuntu']
+    - dfe_has_gnome | default(false)
+
 - name: Configure OS repositories (mirrors, performance)
   ansible.builtin.include_tasks:
     file: repository.yml

ansible/roles/dfe_developer/tasks/nemo.yml

@@ -0,0 +1,57 @@
+---
+# Nemo File Manager - Linux Mint's fork of Nautilus
+# More feature-rich: dual-pane (F3), tree view, plugins, better bulk rename
+# https://github.com/linuxmint/nemo
+#
+# Strategy: Install alongside Nautilus (keeps GNOME integration intact),
+# set Nemo as default file manager for user file browsing.
+
+# ============================================================================
+# FEDORA
+# ============================================================================
+
+- name: Install Nemo file manager (Fedora)
+  ansible.builtin.dnf:
+    name:
+      - nemo
+      - nemo-fileroller  # Archive integration
+      - nemo-preview     # Quick preview with spacebar
+    state: present
+  when: ansible_facts['distribution'] == 'Fedora'
+
+# ============================================================================
+# UBUNTU
+# ============================================================================
+
+# Nemo 6.x available in Ubuntu 24.04 universe - no PPA needed
+- name: Install Nemo file manager (Ubuntu)
+  ansible.builtin.apt:
+    name:
+      - nemo
+      - nemo-fileroller  # Archive integration
+    state: present
+  when: ansible_facts['distribution'] == 'Ubuntu'
+
+# ============================================================================
+# SET AS DEFAULT FILE MANAGER (both distros)
+# ============================================================================
+
+# Set Nemo as default for opening directories
+# This affects "Open Folder" actions throughout the system
+- name: Set Nemo as default file manager
+  ansible.builtin.command:
+    cmd: xdg-mime default nemo.desktop inode/directory
+  become: true
+  become_user: "{{ dfe_actual_user }}"
+  changed_when: true
+  when: ansible_facts['distribution'] in ['Fedora', 'Ubuntu']
+
+# Also set for application/x-gnome-saved-search (saved searches)
+- name: Set Nemo as default for saved searches
+  ansible.builtin.command:
+    cmd: xdg-mime default nemo.desktop application/x-gnome-saved-search
+  become: true
+  become_user: "{{ dfe_actual_user }}"
+  changed_when: true
+  failed_when: false
+  when: ansible_facts['distribution'] in ['Fedora', 'Ubuntu']