Add dry-run support across destructive commands (#516)

* chore: update contributors [skip ci]

* Add dry-run support across destructive commands

Implement dry-run for uninstall, purge, installer, touchid, completion, and remove flows.\nGuard side effects in uninstall path (launchctl, defaults writes, kill/brew actions), update help/README, and add coverage in CLI/Bats tests.\n\nValidation: ./scripts/check.sh and ./scripts/test.sh (452 tests, 0 failures, 8 skipped).

* test(purge): keep dev-compatible purge coverage

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Tw93 <hitw93@gmail.com>

bin/uninstall.sh

@@ -822,10 +822,17 @@ main() {
             "--debug")
                 export MO_DEBUG=1
                 ;;
+            "--dry-run" | "-n")
+                export MOLE_DRY_RUN=1
+                ;;
         esac
     done
 
     hide_cursor
+    if [[ "${MOLE_DRY_RUN:-0}" == "1" ]]; then
+        echo -e "${YELLOW}${ICON_DRY_RUN} DRY RUN MODE${NC}, No app files or settings will be modified"
+        printf '\n'
+    fi
 
     local first_scan=true
     while true; do