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/plans/flight-plan-clean-build.org

@@ -22,7 +22,7 @@ This flight plan defines the strict, step-by-step protocol for escaping the Lisp
 
 * Phase B: Tangle & Audit (The Coder)
 ** TODO 3. Tangle the Literate Source
-- Action: Run =emacs --batch --eval '(require (quote ob-tangle))' --eval '(org-babel-tangle-file "~/memex/projects/opencortex/docs/README.org")'=
+- Action: Run =emacs --batch --eval '(require (quote ob-tangle))' --eval '(org-babel-tangle-file "~/memex/projects/passepartout/docs/README.org")'=
 - Verification: The command must exit with code 0 and report that blocks were tangled.
 
 ** TODO 4. Audit the Physical Lisp Files