chore(audit): create empty src/code_path_audit.py v2

Module docstring + from __future__ import annotations. No code
yet; the data model goes in next (Phase 1).

src/code_path_audit.py

@@ -0,0 +1,11 @@
+"""Code path & data pipeline audit tool v2.
+
+Builds a Producer-Consumer Graph (PCG) of src/, classifies each
+data aggregate by MemoryDim, detects the access pattern (APD),
+estimates the call frequency (CFE), computes the decomposition
+cost (componentize vs unify), cross-validates with 6 existing
+audit scripts, and emits per-aggregate profiles in the v2 custom
+postfix DSL + markdown + prefix tree text. See
+conductor/tracks/code_path_audit_20260607/spec_v2.md.
+"""
+from __future__ import annotations