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

notes/.#gemini-vision.org

@@ -1 +0,0 @@
-user@amr.154851:1777155215

notes/gemini-vision.org

@@ -234,5 +234,5 @@ This is not a product. It is a philosophy made manifest in code.
 * References
 
 - [[file:chats-with-gemini.org][Full Chat Transcripts]]
-- [[file:../projects/opencortex/README.org][OpenCortex README]]
-- [[file:../projects/opencortex/docs/ROADMAP.org][OpenCortex Roadmap]]
+- [[file:../projects/passepartout/README.org][OpenCortex README]]
+- [[file:../projects/passepartout/docs/ROADMAP.org][OpenCortex Roadmap]]