refactor(scripts): move 7 code_path_audit files from src/ to scripts/code_path_audit/

The 7 code_path_audit*.py files (2604 lines total) are pure static
analysis tools. They do AST traversal of src/, no intrusive profiling,
no runtime markers. They were inlaid with src/ but only import:
- src.result_types (the Result[T] convention type)
- each other (the 6 siblings)

After the move:
- src/ is now pure application code; line-count audit metrics are clean
- scripts/code_path_audit/ is a new namespace-isolated subdir per
  AGENTS.md 'scripts are namespace-isolated by directory' rule

TIER-3 READ AGENTS.md + conductor/workflow.md + conductor/edit_workflow.md
+ conductor/code_styleguides/code_path_audit.md + the 7 files before
this commit.

Changes:
- 7 files moved: src/code_path_audit*.py -> scripts/code_path_audit/
- 7 files updated: internal imports rom src.code_path_audit_X ->
  rom code_path_audit_X (siblings in same subdir)
- 7 files updated: add sys.path.insert(0, str(Path(__file__).resolve().parents[2] / 'src'))
  to find src.result_types when run standalone
- 5 test files updated: rom src.code_path_audit -> rom code_path_audit
  + sys.path setup to find the new subdir
- 6 throwaway scripts in scripts/tier2/artifacts/ updated: import path
  + sys.path setup (parents[3] / 'src' + parents[3] / 'scripts' / 'code_path_audit')
- 2 styleguide/spec references updated: conductor/code_styleguides/code_path_audit.md
  + conductor/tracks/code_path_audit_20260607/spec_v2.md
- 1 meta-audit docstring updated: scripts/audit_code_path_audit_coverage.py
- 1 type registry entry deleted: docs/type_registry/src_code_path_audit.md
  (the type is no longer in src/)
- 1 type registry index updated: docs/type_registry/index.md (22 files, was 23)

Verification:
- 7/7 audit gates pass --strict (weak_types 102<=112, type_registry 22 files,
  main_thread_imports OK, no_models_config_io OK, code_path_audit_coverage 0
  violations, exception_handling 0 violations, optional_in_3_files 0 violations)
- 6/6 test files pass: test_code_path_audit, test_code_path_audit_integration,
  test_code_path_audit_phase78, test_code_path_audit_phase89,
  test_code_path_audit_ssdl_behavioral, test_metadata_nil_sentinel
- src/ line count: 29997 lines (down from 32621 = -2624 lines)
- scripts/code_path_audit/ line count: 2620 lines

scripts/tier2/artifacts/code_path_audit_20260607/_gen_report2.py

@@ -404,7 +404,7 @@ uv run python scripts/audit_main_thread_imports.py --json > tests/artifacts/audi
 uv run python scripts/generate_type_registry.py --json > tests/artifacts/audit_inputs/type_registry.json
 
 # Run the v2 audit
-uv run python -c "from src.code_path_audit import run_audit, render_rollups; from pathlib import Path; result = run_audit(src_dir='src', audit_inputs_dir='tests/artifacts/audit_inputs', output_dir='docs/reports/code_path_audit', date='2026-06-22'); render_rollups(result.data, Path('docs/reports/code_path_audit/2026-06-22'))"
+uv run python -c "import sys; sys.path.insert(0, 'scripts/code_path_audit'); from code_path_audit import run_audit, render_rollups; from pathlib import Path; result = run_audit(src_dir='src', audit_inputs_dir='tests/artifacts/audit_inputs', output_dir='docs/reports/code_path_audit', date='2026-06-22'); render_rollups(result.data, Path('docs/reports/code_path_audit/2026-06-22'))"
 
 # Run the meta-audit
 uv run python scripts/audit_code_path_audit_coverage.py --input-dir docs/reports/code_path_audit/2026-06-22/ --strict

scripts/tier2/artifacts/code_path_audit_20260607/_generate_audit_report.py

@@ -605,7 +605,7 @@ code("uv run python scripts/generate_type_registry.py --json > tests/artifacts/a
 code("")
 code("# Run the v2 audit")
 code("uv run python -c \"")
-code("from src.code_path_audit import run_audit, render_rollups")
+code("import sys; sys.path.insert(0, 'scripts/code_path_audit'); from code_path_audit import run_audit, render_rollups")
 code("from pathlib import Path")
 code("result = run_audit(src_dir='src', audit_inputs_dir='tests/artifacts/audit_inputs', output_dir='docs/reports/code_path_audit', date='2026-06-22')")
 code("render_rollups(result.data, Path('docs/reports/code_path_audit/2026-06-22'))")