tools: add repl-block, check-tangle; move existing tools into memex

New tools (projects/<tool>/ — standalone, git-committed):
- repl-block: extract and pipe lisp blocks from org files to the REPL
- check-tangle: tangle + compile in one step, reports errors

Existing tools moved from ~/.opencode/bin/ into memex (survives reinstalls):
- repl, tangle, org-eval, verify-repl

AGENTS.md updated:
- Tool reference table with all 7 tools
- Package reference table for passepartout and cl-tty
- Updated tangle command to use project-local tools

.opencode/commands/ added: check-parens, repl-block, check-tangle commands

.opencode/commands/check-parens.md

@@ -0,0 +1,8 @@
+---
+description: Check paren balance in lisp blocks of .org files
+---
+
+Run `projects/check-parens/check-parens` on the given .org files to verify all
+`#+begin_src lisp` blocks have balanced parentheses.
+
+Usage: /check-parens <file.org> [<file.org> ...]

.opencode/commands/check-tangle.md

@@ -0,0 +1,8 @@
+---
+description: Tangle an org file and compile the result
+---
+
+Tangle an .org file to .lisp then compile with SBCL. Reports the first
+compile error. Exit 0 = clean, exit 1 = compilation error.
+
+Usage: /check-tangle <file.org>

.opencode/commands/repl-block.md

@@ -0,0 +1,13 @@
+---
+description: Send a lisp block from an org file to the REPL
+---
+
+Extract a `#+begin_src lisp` block from an .org file and send it to the
+running daemon REPL.
+
+Usage: /repl-block <file.org> --function <name>
+       /repl-block <file.org> --block <number>
+       /repl-block <file.org> --function <name> --package <pkg>
+
+The --package flag wraps the block in an (in-package ...) form.
+Use --block to identify by 1-based index, --function to find by defun name.