feat: ssr mackup scan|list|clean — on-demand cfg generation with confirmation

Instead of silently writing ~/.mackup/ssr-*.cfg on every sync, generation
is now an explicit opt-in command: ssr mackup scan

  ssr mackup scan   — dry-run: shows NEW/UPD/DEL changes, prompts before writing
  ssr mackup list   — list existing generated files
  ssr mackup clean  — remove all generated files (with confirmation)

ssr sync no longer calls generate_custom_cfg automatically.
Completions updated for zsh, bash, fish.

Co-authored-by: Cursor <cursoragent@cursor.com>

completions/_ssr

@@ -15,6 +15,7 @@ _ssr() {
         'config:Show or edit the active config file'
         'completions:Install or remove shell completions'
         'status:Show last sync time, cloud target, schedule state'
+        'mackup:Manage auto-generated Mackup app definitions'
         'version:Print version'
         'help:Show top-level help'
     )
@@ -59,6 +60,12 @@ _ssr() {
                         'uninstall[Remove shell completions]' \
                         'status[Show installed completions]'
                     ;;
+                mackup)
+                    _values 'mackup action' \
+                        'scan[Suggest and confirm ssr-*.cfg files]' \
+                        'list[List generated ssr-*.cfg files]' \
+                        'clean[Remove all generated ssr-*.cfg files]'
+                    ;;
             esac
             ;;
     esac

completions/ssr.bash

@@ -13,7 +13,7 @@ _ssr() {
         cword=$COMP_CWORD
     fi
 
-    local commands="install sync restore update schedule config completions status version help"
+    local commands="install sync restore update schedule config completions status mackup version help"
     local global_flags="-c --config -h --help"
 
     # Detect command (first non-flag word after `ssr`).
@@ -60,6 +60,9 @@ _ssr() {
         completions)
             COMPREPLY=( $(compgen -W "install uninstall status" -- "$cur") )
             ;;
+        mackup)
+            COMPREPLY=( $(compgen -W "scan list clean" -- "$cur") )
+            ;;
         *)
             COMPREPLY=()
             ;;

completions/ssr.fish

@@ -1,7 +1,7 @@
 # fish completion for ssr — System Sync & Restore.
 # Install: drop into ~/.config/fish/completions/ssr.fish
 
-set -l ssr_cmds install sync restore update schedule config completions status version help
+set -l ssr_cmds install sync restore update schedule config completions status mackup version help
 
 # True when no subcommand has been picked yet (only flags / option-args seen so far).
 function __ssr_needs_subcmd
@@ -69,3 +69,5 @@ complete -c ssr -n '__ssr_using_subcmd update'  -s n -l dry-run -d 'Preview with
 complete -c ssr -n '__ssr_using_subcmd schedule' -a 'on off status'
 complete -c ssr -n '__ssr_using_subcmd config'   -a 'show edit path'
 complete -c ssr -n '__ssr_using_subcmd completions' -a 'install uninstall status'
+complete -c ssr -n __ssr_needs_subcmd -a mackup      -d 'Manage Mackup app definitions'
+complete -c ssr -n '__ssr_using_subcmd mackup'   -a 'scan list clean'