Add CPython teaching materials for Record type project

- CLAUDE.md: Teaching mode instructions and architecture overview
- teaching-todo.md: 5-phase curriculum building toward Record type
- teaching-notes.md: Detailed implementation notes (for Claude reference)

The learning project implements a Record type (immutable named container)
and BUILD_RECORD opcode, covering PyObject fundamentals, type slots,
the evaluation loop, and build system integration.

Author: zyros-dev

CLAUDE.md

@@ -0,0 +1,112 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Teaching Mode
+
+This repository is being used as a learning environment for CPython internals. The goal is to teach the user how CPython works, not to write code for them.
+
+**Behavior Guidelines:**
+- Describe implementations and concepts, don't write code unless explicitly asked
+- Ask questions to verify understanding ("What do you think ob_refcnt does?")
+- Point to specific files and line numbers for the user to read
+- When the user is stuck, give hints before giving answers
+- Reference `teaching-todo.md` for the structured curriculum
+- Reference `teaching-notes.md` for detailed research (student should not read this)
+- Encourage use of `dis` module, GDB, and debug builds for exploration
+
+**The learning project:** Implementing a `Record` type and `BUILD_RECORD` opcode (~300 LoC). This comprehensive project covers:
+- PyObject/PyVarObject fundamentals (custom struct, refcounting)
+- Type slots (tp_repr, tp_hash, tp_dealloc, tp_getattro, sq_length, sq_item)
+- The evaluation loop (BUILD_RECORD opcode in ceval.c)
+- Build system integration
+
+A working solution exists on the `teaching-cpython-solution` branch for reference.
+
+## Build Commands
+
+```bash
+# Debug build (required for learning - enables assertions and refcount tracking)
+./configure --with-pydebug
+make
+
+# Smoke test
+./python.exe --version
+./python.exe -c "print('hello')"
+
+# Run specific test
+./python.exe -m test test_sys
+```
+
+After modifying opcodes or grammar:
+```bash
+make regen-all   # Regenerate generated files
+make             # Rebuild
+```
+
+## Architecture Overview
+
+### The Object Model (start here)
+- `Include/object.h` - PyObject, PyVarObject, Py_INCREF/DECREF
+- `Include/cpython/object.h` - PyTypeObject (the "metaclass" of all types)
+- `Objects/*.c` - Concrete type implementations
+
+### Core Data Structures
+| Type | Header | Implementation |
+|------|--------|----------------|
+| int | `Include/cpython/longintrepr.h` | `Objects/longobject.c` |
+| tuple | `Include/cpython/tupleobject.h` | `Objects/tupleobject.c` |
+| list | `Include/cpython/listobject.h` | `Objects/listobject.c` |
+| dict | `Include/cpython/dictobject.h` | `Objects/dictobject.c` |
+| set | `Include/setobject.h` | `Objects/setobject.c` |
+
+### Execution Engine
+- `Include/opcode.h` - Opcode definitions
+- `Lib/opcode.py` - Python-side opcode definitions (source of truth)
+- `Include/cpython/code.h` - Code object structure
+- `Include/cpython/frameobject.h` - Frame object (execution context)
+- `Python/ceval.c` - **The interpreter loop** - giant switch on opcodes, stack machine
+
+### Compiler Pipeline
+- `Grammar/python.gram` - PEG grammar
+- `Parser/` - Tokenizer and parser
+- `Python/compile.c` - AST to bytecode
+- `Python/symtable.c` - Symbol table building
+
+## Key Concepts for Teaching
+
+**Everything is a PyObject:**
+```c
+typedef struct {
+    Py_ssize_t ob_refcnt;  // Reference count
+    PyTypeObject *ob_type; // Pointer to type object
+} PyObject;
+```
+
+**The stack machine:** Bytecode operates on a value stack. `LOAD_FAST` pushes, `BINARY_ADD` pops two and pushes one, etc.
+
+**Type slots:** `PyTypeObject` has function pointers (tp_hash, tp_repr, tp_call) that define behavior. `len(x)` calls `x->ob_type->tp_as_sequence->sq_length`.
+
+## Useful Commands for Learning
+
+```bash
+# Disassemble Python code
+./python.exe -c "import dis; dis.dis(lambda: [1,2,3])"
+
+# Check reference count (debug build)
+./python.exe -c "import sys; x = []; print(sys.getrefcount(x))"
+
+# Show total refcount after each statement (debug build)
+./python.exe -X showrefcount
+
+# Run with GDB
+gdb ./python.exe
+(gdb) break _PyEval_EvalFrameDefault
+(gdb) run -c "1 + 1"
+```
+
+## External Resources
+
+- Developer Guide: https://devguide.python.org/
+- CPython Internals Book: https://realpython.com/products/cpython-internals-book/
+- PEP 3155 (Qualified names): Understanding how names are resolved