feat(p10-1b): tree-sitter-python AST extractor (PythonAstExtractor)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/kebab-parse-code/tests/fixtures/sample.py

@@ -0,0 +1,26 @@
+"""sample fixture."""
+import os
+
+ANSWER = 42
+
+@staticmethod
+def free(x):
+    """free fn."""
+    return x + 1
+
+class Foo:
+    """doc."""
+    def double(self, n):
+        return n * 2
+
+    @classmethod
+    def name(cls):
+        return "foo"
+
+class Outer:
+    class Inner:
+        def helper(self):
+            return True
+
+def with_decorator():
+    pass