fix(skill): absent claim term -> INCONCLUSIVE hint; note surge-tuning (final-review minors #3,#4)

- gsc_signal_delta.py: extract `found` local var; add first branch in verdict_hint
  chain so a term absent from both GSC windows yields INCONCLUSIVE (not ARTIFACT).
  Existing ARTIFACT / CONFIRMED-PARTIAL / PARTIAL branches unchanged (elif chain).
- test_gsc_signal_delta.py: add test_absent_claim_term_inconclusive asserting
  found=False and "INCONCLUSIVE" in verdict_hint for a term in neither fixture.
- code/CLAUDE.md: one-line surge-tuning note — verdict_hint/in_top_movers are
  calibrated for upward claims; for drops, inspect top_decliners directly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KuT3W81t88QQFaxY2ruWv2

custom-skills/35-seo-signal-validation/code/CLAUDE.md

@@ -12,6 +12,8 @@ python3 scripts/gsc_signal_delta.py \
 Returns day-normalized site totals, top gainers/decliners, and a `verdict_hint`
 (heuristic only — the final verdict is the skill's job, after L2/L3).
 
+**Surge-tuning note**: `verdict_hint` and `in_top_movers` are calibrated for upward "surge" claims (movers ranked by click gain). For a claimed *drop*, inspect `top_decliners` directly rather than relying on the hint.
+
 ## Getting the exports
 `mcp__dda__gsc_fetch_performance` (property pinned per workspace, e.g. JHR
 `sc-domain:josunhotel.com`) → save the query-dimension rows to a file → run the

custom-skills/35-seo-signal-validation/code/scripts/gsc_signal_delta.py

@@ -106,9 +106,10 @@ def compute_delta(recent, prior, recent_days, prior_days,
         gainer_terms = {g["query"] for g in gainers}
         rc, pc = r_by.get(claim_term, {}), p_by.get(claim_term, {})
         in_movers = claim_term in gainer_terms
+        found = bool(rc or pc)
         share = (rc.get("clicks", 0.0) / rt["clicks"] * 100) if rt["clicks"] else 0.0
         out["claim_term"] = {
-            "term": claim_term, "found": bool(rc or pc),
+            "term": claim_term, "found": found,
             "recent": {"clicks": rc.get("clicks", 0.0),
                        "impressions": rc.get("impressions", 0.0),
                        "position": rc.get("position")},
@@ -118,7 +119,12 @@ def compute_delta(recent, prior, recent_days, prior_days,
             "in_top_movers": in_movers,
             "click_share_pct": round(share, 2),
         }
-        if not in_movers and share < 1.0:
+        if not found:
+            out["verdict_hint"] = (
+                f"'{claim_term}' is absent from both GSC windows (no impressions / "
+                f"likely anonymized) -> INCONCLUSIVE, not refuted; confirm via live "
+                f"SERP + entity layer.")
+        elif not in_movers and share < 1.0:
             out["verdict_hint"] = (
                 f"'{claim_term}' contributes {share:.2f}% of recent clicks and is "
                 f"absent from top movers -> claimed impact likely ARTIFACT; real "

custom-skills/35-seo-signal-validation/code/scripts/test_gsc_signal_delta.py

@@ -40,6 +40,12 @@ def test_day_normalization():
     assert out["site_totals"]["prior"]["clicks_per_day"] == 6.93     # 208/30
 
 
+def test_absent_claim_term_inconclusive():
+    out = compute_delta(RECENT, PRIOR, 28, 30, claim_term="존재하지않는검색어")
+    assert out["claim_term"]["found"] is False
+    assert "INCONCLUSIVE" in out["verdict_hint"]
+
+
 def test_positive_days_required():
     try:
         compute_delta(RECENT, PRIOR, 0, 30)