docs(#54): F-4 legacy annotation + F-5 fixture convention -- AUDIT-01 housekeeping

INTEGRATION-AUDIT-01 (#50) §10.4 / §10.5 housekeeping carry-over.

F-4: annotate 14 remaining legacy Phase R'/Q sample-text hits across 10
src/ files with inline marker `# [legacy Phase R'/Q example -- INTEGRATION-AUDIT-01 §10.4]`.
Comment-only. No string-literal / regex / sample dict value mutated.
fit_verifier.py L612 marker keeps Phase Z partial-live import graph
(FitAnalysis / RoleFit / redistribute / salvage) byte-precise.

F-5: docs-only addendum -- §10.5.1 in INTEGRATION-AUDIT-01-REPORT.md +
tests/CLAUDE.md fixture convention note. No root tests/fixtures/ dir
created; existing tests/phase_z2/fixtures/ convention preserved. Documents
test-only sample-reference allowance vs src/** runtime prohibition.

Out of scope: Phase Z source 11 hits (phase_z2_content_extractor /
failure_router / mapper / retry), production behavior change, #19 work.

Verified: pytest -q tests/phase_z2/ = 157 PASS. git diff +210/-0
(35 src/docs lines + 175 new tests/CLAUDE.md). No behavioral delta.

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

src/block_reference.py

@@ -399,6 +399,7 @@ _SAMPLE_DATA: dict[str, dict[str, Any]] = {
         "center_label": "DX",
         "center_sub": "디지털 전환",
         "items": [
+            # [legacy Phase R'/Q example — INTEGRATION-AUDIT-01 §10.4]
             {"label": "BIM", "color": "#ff6b35"},
             {"label": "GIS", "color": "#00d4aa"},
             {"label": "DT", "color": "#ffd700"},
@@ -406,6 +407,7 @@ _SAMPLE_DATA: dict[str, dict[str, Any]] = {
     },
     "keyword-circle-row": {
         "keywords": [
+            # [legacy Phase R'/Q example — INTEGRATION-AUDIT-01 §10.4]
             {"letter": "B", "label": "BIM", "description": "건물정보모델링"},
             {"letter": "G", "label": "GIS", "description": "지리정보시스템"},
             {"letter": "D", "label": "DX", "description": "디지털 전환"},
@@ -432,6 +434,7 @@ _SAMPLE_DATA: dict[str, dict[str, Any]] = {
         "right_title": "개선",
         "rows": [
             {"left": "수작업", "center": "프로세스", "right": "자동화"},
+            # [legacy Phase R'/Q example — INTEGRATION-AUDIT-01 §10.4]
             {"left": "2D 도면", "center": "설계 도구", "right": "3D BIM"},
         ],
     },