feat(composite): 三路对拍前端可见性——合成层页第二卡(三路对比表+规则判读+特征贡献+冗余chips+空态)+GET challenge 端点(最新件/坏件skip);修 challenger CLI 断链(__main__ guard 缺失=python -m 静默空跑,11-01 stage6 必空,部署验证现场抓获);spec §4.4 落账含 QA 无合成 UI 核实 [vps]

docs/superpowers/specs/2026-09-22-research-to-trading-pipeline-design.md

@@ -109,6 +109,7 @@ F 环是「管道」与「飞轮」的分界：归因发现→可能=衰减触
   - 判读：等权≈ICIR=因子相关性高、加权信息少，安心用简单；LGBM 明显跑赢两者=组合方式升级叙事，且 feature importance 天然产出「组合内各因子贡献」（对接 §4.7 归因）；预期两三个完整月度周期才有判读力；
   - 纪律：challenger 永远影子不进生产；若升级仍走决议 K 考场晋级+用户口令，与实盘升级同构。
   - **班次二落地（2026-10-10）**：`sanguo_factor/challenger_lgbm.py`——v1 池=quant12 在役 12 源（扩池挂后续）；三路=方向调整等权/ICIR 档案加权/LGBM（qlib 基准超参，固定 500 轮——无独立 valid 段不早停，注记在对拍件）；walk-forward=前 11M 训练+末 1M 样外（test 隔离铁律：样外月绝不进训练；codex 复审加固=训练窗末 2 交易日 embargo——build_label 双 shift 前视，不 embargo 则窗口末样本的 label 吃样外月收盘=信息层泄漏；三路统一可评样本 mask、缺源/坏件整月 skip 不产半吊子件）；对拍件=`challenger_lgbm/{host}_{as_of}.json`（三路样外 IC/ICIR/Q5-Q1 多空+feature importance+池冗余注记——`|corr|>0.7` 只记录不剔除，首年观察期剔除留人）；挂月度链 stage6（失败不阻链）；判读需累积≥2-3 个样外月。**宽表源现场核实修正**：月度批 `values/` 导出只含注册表因子（fa 族+composite），永不含 quant12 12 源——stage6 `--values-dir` 改指 stage4 截面盘 `/volume1/stock/factor_cross_section`（daily_section 幂等 merge 累积的 12 源主 parquet，12/12 在位实证），零重算同链上游供给。
+  - **对拍前端可见性（2026-10-10 补，用户质问「合成无 UI」驱动；QA frontend-v2 全端点核实=无合成视图可抄，QA 全自动进化人不下场故合成黑盒——我们在环决策必须有证据面）**：合成层页（/pipeline/composite）下方第二卡「三路对拍 · 加权方式之辩」——`GET /pipeline/composite/challenge` 读报告根 `challenger_lgbm/` 最新件（as_of 最大，坏件 skip）；三路对比表（样外 IC/ICIR/Q5-Q1/有效天数，每列最优高亮）+规则判读行（|ΔIC|≤0.005→「等权≈ICIR 简单加权足够」；LGBM 超 max+0.005→「非线性有增量」）+LGBM 特征贡献条+冗余 chips+「永不进生产/单月不构成结论」免责行；无件=空态文案（11-01 首考）。**修复 CLI 断链（部署验证现场抓获）**：challenger_lgbm.py 尾部漏 `if __name__ == "__main__"` guard——`python -m` 静默导入即退 exit 0，11-01 stage6 会空跑；测试直调 main(argv) 函数全绿掩盖 CLI 缝隙，guard+import sys 已补。**产物双机可见**：challenger 依赖 stage4 截面盘（NAS 数据面，VPS 无）→只在 NAS 跑；VPS 前端展示靠产物件同步 NAS→VPS（验证期手动 scp，常态化挂 11-01 前小班）。
 - **test 隔离条款（2026-10-10 成文，QuantaAlpha 附录 E 纪律借鉴）**：**合成层（含 challenger）权重/训练只用截至 as_of 的数据，表现评估只看 as_of 之后——权重窗与成绩窗永不重叠**。现状核实动作=审计 quant12_v2a 权重计算代码确认滚动结构天然合规（每月 T-12~T 算权、T+1 后出成绩），核实结论落本档。防什么=将来实盘与回测打架时，回测成绩有「未被自己污染」的底气；防将来改动（全历史拟合/未来数据调参类）悄悄破坏。
   核实结论（2026-10-10 审计）：quant12_v2a（quant12_icirfit_v1）fit_window=2018-01~2021-06、h2 考场窗=2021-07-01 起（exam_gate DEFAULT_START，同批同 run 对照）——**无重叠**（考场首日恰后于拟合窗末月，首尾相接）；v2c 滚动天然合规：Y 年制度档案 fit [Y-3 年初, Y-1 年末]、考核 Y 年段（walk-forward），且注册路径只挂载档案冻结权重（load_profile→resolve_weights），评估数据不回流拟合。
 - **版本钉住+影子对照闸门（决议 A）**：策略钉住合成层具体版本；合成层变更（晋级/退役/调权）→新旧版影子对照（起步默认 4 周，首年校准）→用户口令→各策略**择期**升级。可回滚、历史可复现，与推 vps 纪律同构。

frontend/src/api/pipeline.ts

@@ -110,6 +110,28 @@ export interface CompositeFamily {
   note: string
 }
 
+// —— 三路对拍(challenger_lgbm 影子实验产物,月度链 stage6) ——
+
+export interface ChallengeSignal {
+  ic_mean: number | null
+  icir: number | null
+  q5q1: number | null
+  days: number
+}
+
+export interface ChallengeDoc {
+  as_of: string
+  generated_at: string
+  host: string
+  file?: string
+  pool: { names: string[]; size: number }
+  split: { oos_month: string; note: string }
+  signals: Record<'equal' | 'icir' | 'lgbm', ChallengeSignal>
+  feature_importance: Record<string, number>
+  redundancy_flagged: Array<{ a: string; b: string; corr: number } | Record<string, unknown>>
+  lgbm_params: Record<string, unknown>
+}
+
 export interface ResearchCardOption { level: number; action: string; meaning: string; cost: string }
 
 export interface Ruling { month: string; level: number; reason: string; decided_at: string }
@@ -226,6 +248,10 @@ export async function getCompositeVersions(family?: string): Promise<{ family: s
   return { family: data.family, families: data.families, versions: data.items }
 }
 
+export async function getCompositeChallenge(): Promise<{ challenge: ChallengeDoc | null; available: string[]; note: string }> {
+  return apiClient.get('/pipeline/composite/challenge')
+}
+
 export async function getLadder(): Promise<LadderStrategy[]> {
   const { data } = await apiClient.get<{ items: LadderStrategy[] }>('/pipeline/ladder')
   return data.items

frontend/src/views/pipeline/CompositeTree.spec.ts

@@ -56,3 +56,50 @@ describe('CompositeTree.vue', () => {
     expect(w.text()).toContain('该族暂无可展示的版本树')
   })
 })
+
+// —— 三路对拍卡(challenger_lgbm 影子产物) ——
+
+vi.mock('@/api/pipeline', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('@/api/pipeline')>()
+  return { ...actual, getCompositeVersions: vi.fn(), getCompositeChallenge: vi.fn() }
+})
+
+import type { ChallengeDoc } from '@/api/pipeline'
+
+const chalDoc: ChallengeDoc = {
+  as_of: '2026-09-30', generated_at: '2026-09-30T21:40:00', host: 'nas',
+  pool: { names: ['alpha12', 'klow'], size: 2 },
+  split: { oos_month: '2026-09', note: '' },
+  signals: {
+    equal: { ic_mean: 0.05, icir: 0.8, q5q1: 0.01, days: 20 },
+    icir: { ic_mean: 0.0505, icir: 0.81, q5q1: 0.011, days: 20 },
+    lgbm: { ic_mean: 0.062, icir: 0.9, q5q1: 0.012, days: 20 },
+  },
+  feature_importance: { alpha12: 0.6, klow: 0.3 },
+  redundancy_flagged: [{ a: 'alpha12', b: 'klow', corr: 0.73 }],
+  lgbm_params: {},
+}
+
+describe('CompositeTree.vue 三路对拍卡', () => {
+  beforeEach(() => vi.clearAllMocks())
+  it('有件:三路表+判读行+特征贡献+冗余 chip 全渲染', async () => {
+    vi.mocked(api.getCompositeVersions).mockResolvedValue({ family: 'composite_quant12', families: fams, versions: compositeMock })
+    vi.mocked(api.getCompositeChallenge).mockResolvedValue({ challenge: chalDoc, available: ['nas_2026-09-30.json'], note: '' })
+    const w = mount(CompositeTree, { global: { plugins: [ElementPlus] } })
+    await flushPromises()
+    expect(w.text()).toContain('三路对拍 · 加权方式之辩')
+    expect(w.text()).toContain('样外月 2026-09')
+    expect(w.text()).toContain('LGBM 样外领先')            // 0.062 > 0.0505+0.005 判读分支
+    expect(w.text()).toContain('alpha12')                   // 特征贡献
+    expect(w.text()).toContain('↔ klow')                    // 冗余 chip
+    expect(w.text()).toContain('challenger 永不进生产')
+  })
+  it('无件:空态文案(11-01 首考),版本树不受影响', async () => {
+    vi.mocked(api.getCompositeVersions).mockResolvedValue({ family: 'composite_quant12', families: fams, versions: compositeMock })
+    vi.mocked(api.getCompositeChallenge).mockResolvedValue({ challenge: null, available: [], note: '暂无对拍数据——月度链 stage6 每月产出(11-01 首考);challenger 永不进生产(影子实验)' })
+    const w = mount(CompositeTree, { global: { plugins: [ElementPlus] } })
+    await flushPromises()
+    expect(w.text()).toContain('暂无对拍数据')
+    expect(w.text()).toContain('composite_quant12')         // 版本树照常
+  })
+})

frontend/src/views/pipeline/CompositeTree.vue

@@ -1,7 +1,7 @@
 <script setup lang="ts">
 import { computed, onMounted, ref } from 'vue'
-import { getCompositeVersions } from '@/api/pipeline'
-import type { CompositeFamily, CompositeVersion } from '@/api/pipeline'
+import { getCompositeVersions, getCompositeChallenge } from '@/api/pipeline'
+import type { CompositeFamily, CompositeVersion, ChallengeDoc, ChallengeSignal } from '@/api/pipeline'
 import PanelCard from './PanelCard.vue'
 
 const family = ref('')
@@ -20,6 +20,47 @@ async function load() {
     loading.value = false
   }
 }
+
+// —— 三路对拍(等权/ICIR/LGBM 影子实验,challenger_lgbm 月度产物) ——
+const chal = ref<ChallengeDoc | null>(null)
+const chalNote = ref('')
+onMounted(async () => {
+  try {
+    const r = await getCompositeChallenge()
+    chal.value = r.challenge
+    chalNote.value = r.note
+  } catch { chal.value = null; chalNote.value = '对拍件读取失败(不阻断版本树)' }
+})
+
+const CHAL_ROWS: Array<{ key: 'equal' | 'icir' | 'lgbm'; label: string; note: string }> = [
+  { key: 'equal', label: '等权', note: '12 源方向调整后等权(简单基线)' },
+  { key: 'icir', label: 'ICIR', note: '档案权重×方向(在位 v2a 同款逻辑)' },
+  { key: 'lgbm', label: 'LGBM', note: 'walk-forward 样外预测(挑战者)' },
+]
+const sig = (k: 'equal' | 'icir' | 'lgbm'): ChallengeSignal | null => chal.value?.signals?.[k] ?? null
+const fmtNum = (v: number | null | undefined, digits = 4): string =>
+  v == null ? '—' : v.toFixed(digits)
+// 每列最优者高亮:IC/ICIR/Q5Q1 越大越好(方向已调整)
+const bestKey = (field: 'ic_mean' | 'icir' | 'q5q1'): string | null => {
+  const pairs = CHAL_ROWS.map(r => [r.key, sig(r.key)?.[field]] as const)
+    .filter(([, v]) => v != null) as Array<[keyof ChallengeDoc['signals'], number]>
+  if (pairs.length < 2) return null
+  return pairs.reduce((a, b) => (b[1] > a[1] ? b : a))[0]
+}
+const verdictLine = computed(() => {
+  const eq = sig('equal')?.ic_mean, ir = sig('icir')?.ic_mean, lg = sig('lgbm')?.ic_mean
+  if (eq == null || ir == null) return '样外月评分数据不足——下个月度批再看'
+  if (lg != null && lg > Math.max(eq, ir) + 0.005)
+    return 'LGBM 样外领先:非线性权重有增量信号,结合下方特征贡献定去留'
+  return `等权≈ICIR(ΔIC=${Math.abs(eq - ir).toFixed(4)}):因子相关性高,简单加权足够——证据支持现状`
+})
+const impSorted = computed(() =>
+  Object.entries(chal.value?.feature_importance ?? {})
+    .sort((a, b) => b[1] - a[1])
+    .map(([name, v]) => ({ name, v })))
+const impMax = computed(() => (impSorted.value[0]?.v) || 1)
+const redundancy = computed(() => (chal.value?.redundancy_flagged ?? []) as Array<{ a: string; b: string; corr: number }>)
+
 const familyNote = computed(() => families.value.find(f => f.key === family.value)?.note ?? '')
 const pct = (wgt: number): string => `${(wgt * 100).toFixed(1)}%`
 const te = (v: CompositeVersion): string =>
@@ -64,6 +105,47 @@ const te = (v: CompositeVersion): string =>
         </div>
       </div>
     </PanelCard>
+
+    <PanelCard title="三路对拍 · 加权方式之辩" sub="等权 vs ICIR vs LGBM 同池样外对拍(月度链 stage6 影子产物) · challenger 永不进生产——证据攒够才谈换权重,换法走版本钉住流程">
+      <div v-if="!chal" class="chal-empty">{{ chalNote || '暂无对拍数据——月度链每月产出(11-01 首考)' }}</div>
+      <div v-else class="chal">
+        <div class="chal-meta mono">
+          as_of {{ chal.as_of }} · 样外月 {{ chal.split?.oos_month }} · 池 {{ chal.pool?.size }} 源
+          · {{ chal.host }} · {{ (chal.generated_at || '').slice(0, 19) }}
+        </div>
+        <table class="chal-table">
+          <thead>
+            <tr><th>路</th><th>样外 IC</th><th>ICIR</th><th>Q5-Q1 多空</th><th>有效天数</th></tr>
+          </thead>
+          <tbody>
+            <tr v-for="r in CHAL_ROWS" :key="r.key">
+              <td>
+                <span class="chal-name" :class="{ lg: r.key === 'lgbm' }">{{ r.label }}</span>
+                <span class="chal-note">{{ r.note }}</span>
+              </td>
+              <td class="mono" :class="{ win: bestKey('ic_mean') === r.key }">{{ fmtNum(sig(r.key)?.ic_mean) }}</td>
+              <td class="mono" :class="{ win: bestKey('icir') === r.key }">{{ fmtNum(sig(r.key)?.icir) }}</td>
+              <td class="mono" :class="{ win: bestKey('q5q1') === r.key }">{{ fmtNum(sig(r.key)?.q5q1) }}</td>
+              <td class="mono dim">{{ sig(r.key)?.days ?? '—' }}</td>
+            </tr>
+          </tbody>
+        </table>
+        <div class="chal-verdict">{{ verdictLine }}</div>
+        <div class="chal-disclaimer mono">单样外月不构成结论,判读需 ≥2-3 样外月 · 训练窗=样外月前推 11 自然月(末 2 交易日 embargo)</div>
+        <div v-if="impSorted.length" class="imp">
+          <div class="imp-title">LGBM 特征贡献(top)</div>
+          <div v-for="it in impSorted.slice(0, 12)" :key="it.name" class="imp-row">
+            <span class="mono imp-name">{{ it.name }}</span>
+            <div class="imp-bar-bg"><div class="imp-bar" :style="{ width: `${(it.v / impMax) * 100}%` }" /></div>
+            <span class="mono imp-val">{{ it.v.toFixed(3) }}</span>
+          </div>
+        </div>
+        <div v-if="redundancy.length" class="redun">
+          <span class="redun-title">池冗余注记(|corr|&gt;0.7,只记录不剔除——首年观察期)</span>
+          <span v-for="(p, i) in redundancy" :key="i" class="redun-chip mono">{{ p.a }} ↔ {{ p.b }} {{ p.corr?.toFixed(2) }}</span>
+        </div>
+      </div>
+    </PanelCard>
   </div>
 </template>
 
@@ -93,4 +175,26 @@ const te = (v: CompositeVersion): string =>
 .gate { display: flex; align-items: center; gap: 10px; margin-top: 10px; }
 .gate-chip { font-family: var(--mono); font-size: 10.5px; color: var(--text-3); border: 1px dashed var(--border); border-radius: var(--r-sm); padding: 2px 8px; }
 .gate-note { font-size: 10.5px; color: var(--text-3); font-family: var(--mono); }
+
+/* 三路对拍卡 */
+.chal-empty { font-size: 12px; color: var(--text-3); padding: 14px 0; border: 1px dashed var(--border); border-radius: var(--r-sm); text-align: center; }
+.chal-meta { font-size: 10.5px; color: var(--text-3); margin-bottom: 10px; }
+.chal-table { width: 100%; border-collapse: collapse; margin-bottom: 10px; }
+.chal-table th { text-align: left; font-size: 10.5px; font-weight: 400; color: var(--text-3); padding: 4px 10px 6px 0; border-bottom: 1px solid var(--border); }
+.chal-table td { padding: 7px 10px 7px 0; border-bottom: 1px solid var(--border); font-size: 12px; vertical-align: baseline; }
+.chal-table td.win { color: var(--lamp-ok); font-weight: 700; }
+.chal-name { font-weight: 700; margin-right: 8px; }
+.chal-name.lg { color: #ffb84d; }
+.chal-note { font-size: 10.5px; color: var(--text-3); }
+.chal-verdict { font-size: 12.5px; color: var(--text-2); background: rgba(0, 229, 255, 0.06); border-left: 2px solid var(--brand); padding: 8px 12px; border-radius: 0 var(--r-sm) var(--r-sm) 0; margin-bottom: 6px; }
+.chal-disclaimer { font-size: 10px; color: var(--text-3); margin-bottom: 14px; }
+.imp { margin-bottom: 12px; }
+.imp-title, .redun-title { display: block; font-size: 11px; color: var(--text-3); margin-bottom: 8px; }
+.imp-row { display: flex; align-items: center; gap: 10px; margin-bottom: 4px; }
+.imp-name { width: 110px; font-size: 11px; color: var(--text-2); flex-shrink: 0; }
+.imp-bar-bg { flex: 1; height: 8px; background: rgba(255, 255, 255, 0.05); border-radius: 2px; overflow: hidden; }
+.imp-bar { height: 100%; background: linear-gradient(90deg, rgba(0, 229, 255, 0.35), var(--brand)); border-radius: 2px; }
+.imp-val { width: 46px; font-size: 10.5px; color: var(--text-3); text-align: right; flex-shrink: 0; }
+.redun { margin-bottom: 4px; }
+.redun-chip { display: inline-block; font-size: 10.5px; color: #ffb84d; border: 1px solid rgba(255, 184, 77, 0.4); border-radius: var(--r-sm); padding: 2px 8px; margin: 0 6px 6px 0; }
 </style>

sanguo_api/routes_pipeline.py

@@ -945,6 +945,39 @@ def composite(family: str | None = None) -> dict:
             "items": [challenger, incumbent]}
 
 
+@router.get("/pipeline/composite/challenge")
+def composite_challenge() -> dict:
+    """三路对拍最新件(等权/ICIR/LGBM 影子实验,spec §4.4 决议 O 前置可視性).
+
+    读报告根 challenger_lgbm/ 子目录(challenger_lgbm.py 产物,月度链 stage6
+    每月覆盖);多件取 as_of 最大,坏件 skip 留痕.无件=空态(11-01 首考),
+    前端显示"暂无对拍数据"——不造数.
+    """
+    import glob as _glob
+
+    sub = os.path.join(_monthly_dir(), "challenger_lgbm")
+    docs: list[tuple[str, str, dict]] = []  # (as_of, file, doc)
+    for p in sorted(_glob.glob(os.path.join(sub, "*.json"))):
+        try:
+            with open(p, encoding="utf-8") as f:
+                d = json.load(f)
+            as_of = str(d.get("as_of") or "")
+            if as_of:
+                docs.append((as_of, os.path.basename(p), d))
+        except Exception as exc:  # 坏件 skip: 对拍件非权威数据面,宁缺勿崩
+            logger.warning("challenge 对拍件坏件 skip %s: %s", p, exc)
+    if not docs:
+        return {"challenge": None,
+                "available": [],
+                "note": "暂无对拍数据——月度链 stage6 每月产出"
+                        "(11-01 首考);challenger 永不进生产(影子实验)"}
+    docs.sort(key=lambda t: t[0])  # as_of 字典序=时间序
+    _, fname, doc = docs[-1]
+    doc["file"] = fname
+    return {"challenge": doc, "available": [f for _, f, _ in docs],
+            "note": ""}
+
+
 # —— P4-1 假设卡片向导(决议 M:LLM 只做文字→结构,draft 不落库,确认才落) ——
 
 _DRAFT_SENTENCE_MAX = 500

sanguo_factor/challenger_lgbm.py

@@ -10,6 +10,7 @@ from __future__ import annotations
 
 import json
 import os
+import sys
 from pathlib import Path
 
 import numpy as np
@@ -321,3 +322,7 @@ def main(argv: list[str] | None = None) -> int:
         return 0          # 无宽表=非错误(截面盘未建),不阻链
     print(f"[challenger] 对拍件: {path}")
     return 0
+
+
+if __name__ == "__main__":  # python -m 入口(guard 缺失=静默导入即退,月度链空跑)
+    sys.exit(main())

tests/api/test_routes_pipeline_composite.py

@@ -132,3 +132,56 @@ def test_unknown_family_fail_soft(client, env):
     assert doc["family"] == "composite_nope"
     assert doc["items"] == []
     assert doc["families"]          # 清单照常(切换器不空)
+
+
+# —— GET /pipeline/composite/challenge 三路对拍件(challenger_lgbm 月度产物) ——
+
+import json as _json
+
+
+def _put_doc(monthly_dir, name, as_of, ic_eq=0.05, ic_lg=0.06):
+    import os
+    sub = os.path.join(monthly_dir, "challenger_lgbm")
+    os.makedirs(sub, exist_ok=True)
+    doc = {"as_of": as_of, "generated_at": f"{as_of}T21:40:00", "host": "nas",
+           "pool": {"names": ["alpha12"], "size": 1},
+           "split": {"oos_month": as_of[:7], "note": ""},
+           "signals": {"equal": {"ic_mean": ic_eq, "icir": 0.8, "q5q1": 0.01, "days": 20},
+                       "icir": {"ic_mean": ic_eq, "icir": 0.8, "q5q1": 0.01, "days": 20},
+                       "lgbm": {"ic_mean": ic_lg, "icir": 0.9, "q5q1": 0.012, "days": 20}},
+           "feature_importance": {"alpha12": 1.0},
+           "redundancy_flagged": [], "lgbm_params": {}}
+    with open(os.path.join(sub, name), "w", encoding="utf-8") as f:
+        _json.dump(doc, f)
+    return doc
+
+
+def test_challenge_empty_when_no_dir(client, monkeypatch, tmp_path):
+    monkeypatch.setenv("SANGUO_FACTOR_MONTHLY_DIR", str(tmp_path / "none"))
+    r = client.get("/api/v1/pipeline/composite/challenge")
+    assert r.status_code == 200
+    doc = r.json()
+    assert doc["challenge"] is None and doc["available"] == []
+    assert "暂无对拍数据" in doc["note"]
+
+
+def test_challenge_latest_as_of_wins(client, monkeypatch, tmp_path):
+    monkeypatch.setenv("SANGUO_FACTOR_MONTHLY_DIR", str(tmp_path))
+    _put_doc(tmp_path, "nas_2026-08-31.json", "2026-08-31")
+    _put_doc(tmp_path, "nas_2026-09-30.json", "2026-09-30")
+    doc = client.get("/api/v1/pipeline/composite/challenge").json()
+    assert doc["challenge"]["as_of"] == "2026-09-30"
+    assert doc["challenge"]["file"] == "nas_2026-09-30.json"
+    assert sorted(doc["available"]) == ["nas_2026-08-31.json", "nas_2026-09-30.json"]
+    assert doc["challenge"]["signals"]["lgbm"]["ic_mean"] == 0.06
+
+
+def test_challenge_bad_json_skipped(client, monkeypatch, tmp_path):
+    import os
+    monkeypatch.setenv("SANGUO_FACTOR_MONTHLY_DIR", str(tmp_path))
+    _put_doc(tmp_path, "nas_2026-09-30.json", "2026-09-30")
+    with open(os.path.join(tmp_path, "challenger_lgbm", "bad.json"), "w") as f:
+        f.write("{broken")
+    doc = client.get("/api/v1/pipeline/composite/challenge").json()
+    assert doc["challenge"]["as_of"] == "2026-09-30"
+    assert "bad.json" not in doc["available"]