rename: opencortex → passepartout across memex

- .gitmodules: update submodule paths (projects/opencortex → projects/passepartout,
  projects/opencortex-contrib → projects/passepartout-contrib)
- gtd.org, README.org: update project references and display names
- check.lisp, gemini-vision.org, agora/TODO.org: update file paths
- dotemacs: update agenda paths and template config
- system/plans/: update all flight plan references
- system/backups/: update monolithic backup references

system/backups/emacs.org.monolithic.bak

@@ -2127,7 +2127,7 @@ On package.el, it is a manual install so far
 ** OpenCortex
 #+begin_src elisp
    ;; 1. Manually add the path to your load-path
-  (add-to-list 'load-path "~/memex/projects/opencortex/src")
+  (add-to-list 'load-path "~/memex/projects/passepartout/src")
    
    ;; 2. Explicitly load the file
   (require 'opencortex)
@@ -2147,7 +2147,7 @@ On package.el, it is a manual install so far
 
     ;;  (use-package opencortex
     ;; :straight nil
-   ;;     :load-path "~/memex/projects/opencortex/src" ;; Adjust this to your local clone path
+   ;;     :load-path "~/memex/projects/passepartout/src" ;; Adjust this to your local clone path
    ;;     :commands (opencortex-connect opencortex-disconnect)
    ;;     :init
         ;; Remote connection settings