build: embed test scripts into org files and purge tests directory

- Embedded run-all-tests.lisp into harness/package.org.
- Deleted the tests/ directory and orphaned Python test scripts, as all other test files are correctly tangled from their parent org files.

tests/self-edit-tests.lisp

@@ -1,34 +0,0 @@
-(defpackage :opencortex-self-edit-tests
-  (:use :cl :fiveam :opencortex)
-  (:export #:self-edit-suite))
-
-(in-package :opencortex-self-edit-tests)
-
-(def-suite self-edit-suite
-  :description "Tests for Self-Edit skill.")
-
-(in-suite self-edit-suite)
-
-(test balance-parens-balanced
-  (let ((result (opencortex::self-edit-balance-parens "(+ 1 2)")))
-    (is (string= result "(+ 1 2)"))
-    (is (not (null (read-from-string result))))))
-
-(test balance-parens-missing-open
-  (let ((result (opencortex::self-edit-balance-parens "+ 1 2)")))
-    (is (string= result "(+ 1 2)"))
-    (is (not (null (read-from-string result))))))
-
-(test balance-parens-missing-close
-  (let ((result (opencortex::self-edit-balance-parens "(+ 1 2")))
-    (is (string= result "(+ 1 2)"))
-    (is (not (null (read-from-string result))))))
-
-(test balance-parens-deep
-  (let ((result (opencortex::self-edit-balance-parens "((lambda (x) (if x (+ 1 2) 3))")))
-    (is (string= result "((lambda (x) (if x (+ 1 2) 3)))"))
-    (is (not (null (read-from-string result))))))
-
-(test balance-parens-empty
-  (let ((result (opencortex::self-edit-balance-parens "")))
-    (is (string= result ""))))