build: dynamically tangle to INSTALL_DIR without copying .org files

- Updated all 150+ :tangle headers across harness/ and skills/ to use elisp (expand-file-name) to target INSTALL_DIR dynamically.
- Cleaned up environment/ directory depth by moving memory-image.lisp to state/.
- Moved test scripts to tests/ and deleted redundant chat scripts.

minimal.asd

@@ -0,0 +1,4 @@
+(defsystem :opencortex-minimal
+  :name "opencortex-minimal"
+  :depends-on ()
+  :components ((:file "harness/package")))