refactor: migrate to role-based variable management and blockinfile config

roles/cs_student/tasks/main.yml

@@ -38,16 +38,12 @@
     creates: ~/.emacs.d
 
 - name: Setup shell aliases
-  lineinfile:
-    path: "{{ lookup('env', 'HOME') }}/.zshrc"
-    line: "{{ item }}"
-    create: yes
-  loop:
-    - alias ls='eza --icons --group-directories-first'
-    - alias ll='eza -la --icons --group-directories-first'
-    - alias cat='bat --style=auto'
-    - alias find='fd'
-    - alias top='btm'
-    - alias tre='broot --sizes'
-    - alias e='emacs -nw'
-    - alias vim='nvim'
+  blockinfile:
+    path: "{{ archsetup_user_home }}/.zshrc"
+    marker: "# {mark} ANSIBLE MANAGED - CS STUDENT"
+    block: |
+      # CS student aliases
+      alias find='fd'
+      alias top='btm'
+      alias tre='broot --sizes'
+      alias e='emacs -nw'