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-recursive-kernel.org

@@ -4,9 +4,9 @@
 Implement a recursive `cognitive-cycle` that allows the agent to chain multiple actions (tool calls) and observe results before finalising a response, similar to SOTA agents like Claude Code.
 
 ## Key Files & Context
-- `projects/opencortex/docs/README.org`: The primary source of truth for the kernel logic.
-- `projects/opencortex/src/core.lisp`: Tangled kernel implementation.
-- `projects/opencortex/src/symbolic.lisp`: Contains the `decide` logic.
+- `projects/passepartout/docs/README.org`: The primary source of truth for the kernel logic.
+- `projects/passepartout/src/core.lisp`: Tangled kernel implementation.
+- `projects/passepartout/src/symbolic.lisp`: Contains the `decide` logic.
 
 ## Implementation Steps