refactor(standardize): remove dead code, fix inconsistencies, update docs

- Remove unused sudo_lecture.txt.j2 template (never referenced)
- Add vars_proxmox.yml and .sisyphus/ to .gitignore
- Remove redundant inner when conditions in cleanup/vmware.yml
- Standardize bootstrap_var_key usage in alpine, opensuse, void tasks
- Normalize sysctl key=value formatting (remove inconsistent spaces)
- Add vars_baremetal_example.yml to README examples list
- Remove unnecessary changed_when on set_fact in hypervisor.yml

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

roles/configuration/templates/sudo_lecture.txt.j2

@@ -1,11 +0,0 @@
-
-       \^V//
-       |. .|    I AM (G)ROOT!
-     - \ - / _
-      \_| |_/
-        \ \
-      __/_/__
-     |_______|   With great power comes great responsibility.
-      \     /    Use sudo wisely.
-       \___/
-