wip: phase_z2 evidence 파이프라인 + matching 실험(phase2~26) + 프론트 trace 패널 진행분 스냅샷

- src: phase_z2 composition/mapper/pipeline/placement_planner/retry, ai_fallback(prompts/schema/validate), mdx_text_atoms 신규
- Front: PipelineTracePanel 신규, FramePanel/SlideCanvas/Home/designAgentApi 등 갱신 + 테스트 4종 추가
- templates/phase_z2: catalog(component_expansion_registry, node_slot_mapping 신규), frames, families, slide_base 갱신
- tests/matching: phase2~26 매칭 실험 스크립트·리포트·온톨로지 전체 (미커밋 진행분)
- tests: b4_v4 evidence, task5~28.5 시리즈, regression(imp95 baseline) 등 신규 테스트 대량 추가
- docs/reference: MDX 구조 인벤토리, MDX→Frame 구조 계약 문서
- scripts: mdx 계약/parity/coverage/viewport 체크, gitea comment, run sync 유틸
- .gitignore: tmp*.json, chromedriver, .orchestrator, *.pkl, Front_test* 등 임시/스냅샷 제외

미완성 작업의 보존용 스냅샷 커밋 (2026-07-02)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Front/client/src/components/FramePanel.tsx

@@ -99,6 +99,9 @@ export default function FramePanel({
         {candidates.length === 0 ? (
           <div className="py-20 text-center border-2 border-dashed border-slate-50 rounded-2xl">
              <p className="text-[10px] font-bold text-slate-300 uppercase">No Candidates Available</p>
+             <p className="mt-2 px-4 text-[10px] leading-relaxed text-slate-400">
+               backend candidate pool is empty for {assignedSectionIds.join(", ") || selectedZone.zone_id}.
+             </p>
           </div>
         ) : (
           candidates.map((candidate, index) => {
@@ -120,6 +123,7 @@ export default function FramePanel({
               candidate.routeHint && candidate.routeHint !== "direct_render";
             const showStatusChip =
               candidate.phaseZStatus && candidate.phaseZStatus !== "auto_renderable";
+            const showCoverageChip = Boolean(candidate.coverageState);
             const hasCapacityFit =
               candidate.capacityFit && candidate.capacityFit.fit_status;
             const capacityMismatch =
@@ -132,6 +136,10 @@ export default function FramePanel({
             if (candidate.routeHint) evidenceLines.push(`route: ${candidate.routeHint}`);
             if (candidate.phaseZStatus)
               evidenceLines.push(`phase_z_status: ${candidate.phaseZStatus}`);
+            if (candidate.candidateStatus)
+              evidenceLines.push(`candidate_status: ${candidate.candidateStatus}`);
+            if (candidate.coverageState)
+              evidenceLines.push(`coverage_state: ${candidate.coverageState}`);
             if (hasCapacityFit) {
               const cf = candidate.capacityFit!;
               const capacityLine =
@@ -279,6 +287,28 @@ export default function FramePanel({
                              {candidate.label}
                            </span>
                          )}
+                         {showCoverageChip && (
+                           <span
+                             className={`text-[8px] font-black uppercase tracking-tight px-1.5 py-0.5 rounded ${
+                               candidate.coverageState === "covered_native"
+                                 ? "bg-emerald-50 text-emerald-700"
+                                 : candidate.coverageState === "covered_via_expand"
+                                 ? "bg-cyan-50 text-cyan-700"
+                                 : candidate.coverageState === "requires_adaptation"
+                                 ? "bg-amber-50 text-amber-700"
+                                 : "bg-slate-100 text-slate-600"
+                             }`}
+                             title={`coverage_state: ${candidate.coverageState}`}
+                           >
+                             {candidate.coverageState === "covered_native"
+                               ? "native"
+                               : candidate.coverageState === "covered_via_expand"
+                               ? "expand"
+                               : candidate.coverageState === "requires_adaptation"
+                               ? "adapt"
+                               : "unsup"}
+                           </span>
+                         )}
                          {/* IMP-29 u3 — route hint chip (skip when direct_render = default). */}
                          {showRouteChip && (
                            <span