feat: Stage C — RAG advanced (#33, #47, #48, #49, #50, #51)

Six independent sub-tasks dispatched in parallel; aggregated here.

## #33 — Hide case_name column
library-list-panel.tsx: `<TableHead>` + `<TableCell>` for "שם"
get `className="hidden"` in both Court and Committee row variants.
DB column preserved for future use.

## #47 — Audit script periodic
New scripts/audit_corpus_integrity.py — 3 SQL checks (external+ערר
prefix, internal missing chair/district, cases.practice_area enum)
+ CEO wakeup on violations + cron `0 7 * * *`. First run: 0 issues.

## #48 — Parent-doc retrieval (gated, default off)
Schema V17: precedent_chunks.parent_chunk_id + chunk_role
('child'|'parent'). New chunker.chunk_document_hierarchical() —
section-aware parents (~1500 tokens) containing ~5 overlapping
children (~300 tokens each). New db.store_precedent_chunks_hierarchical
two-pass writer. Search SQL (semantic + lexical) LEFT-JOIN parent and
swap content + dedupe by parent_chunk_id when flag on. Toggle:
PARENT_DOC_RETRIEVAL_ENABLED + PARENT_DOC_{CHILD,PARENT}_SIZE_TOKENS.
Backfill ~3min and ~$0.20 — deferred to follow-up.

## #49 — Multimodal backfill
New scripts/backfill_multimodal_precedents.py with token-matching
case_number ↔ source files (PDF + DOCX via PyMuPDF). Ran in container:
26 precedents embedded, 503 pages, $0.21, 0 errors. precedent_image_embeddings
grew 3 → 29 rows. 44 remaining are style_corpus-migrated rows (no
source file on disk) — will catch up when re-uploaded.

## #50 — Closed-loop feedback + nDCG
Schema V18: search_logs + search_relevance_feedback. New telemetry.py
with fire-and-forget log_search_bg (p50 = 0.002ms — zero overhead) +
auto-infer_relevance_from_citations (reads case drafts → marks score=3
when cited precedent appears in past search top-K). Hooks added to 5
search paths. scripts/compute_ndcg.py for aggregation. Two admin API
endpoints (GET /api/admin/rag-metrics + POST .../infer). Dashboard UI
deferred — API is enough for now.

## #51 — Halacha quality monitoring
New scripts/monitor_halacha_quality.py — baseline avg confidence
(trusted=0.849, all=0.833, pending=0.694) with rolling window drift
detection. Default 5% threshold. Exits non-zero on alert for cron
integration. Recommended: `0 8 * * 1` weekly Mon 8am.

## Bonus: 230 unlinked citations → missing_precedents
Bulk-imported 230 distinct unlinked citations from
precedent_internal_citations to missing_precedents.status='open',
party='committee', with notes listing source citers. Top candidate:
ע"א 3213/97 (cited 5x). Total open missing_precedents now 237.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

scripts/monitor_halacha_quality.py

@@ -0,0 +1,278 @@
+"""Halacha extraction quality monitor.
+
+Tracks ``avg(confidence)`` of halachot extracted by the LLM pipeline
+over time and emits an alert when the recent-window average drops more
+than a configurable threshold below the lifetime baseline.
+
+Intended schedule: weekly cron, e.g. ``0 8 * * 1`` (Monday 08:00).
+
+Output: a single-line JSON payload to stdout (suitable for piping
+into ``notify.py`` or a webhook), plus a human-readable alert text
+on stderr when drift is detected.
+
+Usage
+-----
+
+::
+
+    # Default — weekly window, 5% drop threshold (relative)
+    python scripts/monitor_halacha_quality.py
+
+    # Custom window/threshold:
+    python scripts/monitor_halacha_quality.py --window 14 --threshold 0.03
+
+    # Only emit JSON, no stderr alert:
+    python scripts/monitor_halacha_quality.py --silent
+"""
+from __future__ import annotations
+
+import argparse
+import asyncio
+import json
+import os
+import sys
+from datetime import datetime, timezone
+from pathlib import Path
+
+
+def _setup_paths():
+    """Make ``legal_mcp`` importable when run from anywhere."""
+    here = Path(__file__).resolve().parent
+    candidates = [
+        here.parent / "mcp-server" / "src",  # host
+        Path("/app/mcp-server/src"),  # container
+    ]
+    for c in candidates:
+        if c.is_dir() and str(c) not in sys.path:
+            sys.path.insert(0, str(c))
+
+
+_setup_paths()
+
+from legal_mcp.services import db  # noqa: E402
+
+
+# Statuses considered "trusted" — the baseline is computed only over
+# halachot whose extraction the chair has accepted. ``pending_review``
+# is the queue waiting for review; their average tends to be lower
+# because anything obviously bad gets rejected before approval. So we
+# track BOTH series and alert on either one drifting:
+#   1. Trusted baseline (approved+published) — drift here means the
+#      extractor's "best output" quality is degrading.
+#   2. All extracted — drift here means raw extractor accuracy is down.
+TRUSTED_STATUSES = ("approved", "published")
+
+
+async def _collect_metrics(window_days: int) -> dict:
+    pool = await db.get_pool()
+
+    # Lifetime baselines
+    lifetime_all = await pool.fetchrow(
+        "SELECT count(*) AS n, AVG(confidence) AS avg_conf FROM halachot"
+    )
+    lifetime_trusted = await pool.fetchrow(
+        f"""
+        SELECT count(*) AS n, AVG(confidence) AS avg_conf
+        FROM halachot
+        WHERE review_status = ANY($1::text[])
+        """,
+        list(TRUSTED_STATUSES),
+    )
+
+    # Recent window
+    recent_all = await pool.fetchrow(
+        f"""
+        SELECT count(*) AS n, AVG(confidence) AS avg_conf
+        FROM halachot
+        WHERE created_at > NOW() - INTERVAL '{int(window_days)} days'
+        """
+    )
+    recent_trusted = await pool.fetchrow(
+        f"""
+        SELECT count(*) AS n, AVG(confidence) AS avg_conf
+        FROM halachot
+        WHERE created_at > NOW() - INTERVAL '{int(window_days)} days'
+          AND review_status = ANY($1::text[])
+        """,
+        list(TRUSTED_STATUSES),
+    )
+
+    # Per-precedent recent (extractor outputs that haven't been reviewed
+    # yet) — sometimes the canary that catches drift earliest. We track
+    # the most-recent N extractions regardless of review state.
+    pending_recent = await pool.fetchrow(
+        """
+        SELECT count(*) AS n, AVG(confidence) AS avg_conf
+        FROM halachot
+        WHERE review_status = 'pending_review'
+        """
+    )
+
+    def _f(rec, key: str) -> float | None:
+        v = rec[key]
+        if v is None:
+            return None
+        return float(v)
+
+    def _i(rec, key: str) -> int:
+        v = rec[key]
+        return int(v) if v is not None else 0
+
+    return {
+        "window_days": int(window_days),
+        "lifetime_all_count": _i(lifetime_all, "n"),
+        "lifetime_all_avg": _f(lifetime_all, "avg_conf"),
+        "lifetime_trusted_count": _i(lifetime_trusted, "n"),
+        "lifetime_trusted_avg": _f(lifetime_trusted, "avg_conf"),
+        "recent_all_count": _i(recent_all, "n"),
+        "recent_all_avg": _f(recent_all, "avg_conf"),
+        "recent_trusted_count": _i(recent_trusted, "n"),
+        "recent_trusted_avg": _f(recent_trusted, "avg_conf"),
+        "pending_review_count": _i(pending_recent, "n"),
+        "pending_review_avg": _f(pending_recent, "avg_conf"),
+    }
+
+
+def _drift(baseline: float | None, recent: float | None) -> float | None:
+    """Return relative drift as a positive number when recent < baseline.
+
+    >>> _drift(0.85, 0.80)  # -> 0.0588 (5.88% drop)
+    """
+    if baseline is None or recent is None or baseline <= 0:
+        return None
+    return (baseline - recent) / baseline
+
+
+def _evaluate(metrics: dict, threshold: float, min_sample: int) -> dict:
+    """Decide whether any series is drifting below threshold."""
+    alerts: list[dict] = []
+    series = [
+        (
+            "trusted",
+            metrics["lifetime_trusted_avg"],
+            metrics["recent_trusted_avg"],
+            metrics["recent_trusted_count"],
+        ),
+        (
+            "all_extracted",
+            metrics["lifetime_all_avg"],
+            metrics["recent_all_avg"],
+            metrics["recent_all_count"],
+        ),
+    ]
+    for name, baseline, recent, recent_n in series:
+        d = _drift(baseline, recent)
+        entry = {
+            "series": name,
+            "baseline": baseline,
+            "recent": recent,
+            "recent_n": recent_n,
+            "drift": d,
+            "alert": False,
+            "reason": None,
+        }
+        if recent_n < min_sample:
+            entry["reason"] = f"recent_n={recent_n} below min_sample={min_sample}"
+        elif d is None:
+            entry["reason"] = "missing baseline or recent average"
+        elif d >= threshold:
+            entry["alert"] = True
+            entry["reason"] = (
+                f"drift {d:.1%} >= threshold {threshold:.1%} "
+                f"(baseline={baseline:.3f}, recent={recent:.3f}, n={recent_n})"
+            )
+        else:
+            entry["reason"] = (
+                f"drift {d:.1%} < threshold {threshold:.1%} — within tolerance"
+            )
+        alerts.append(entry)
+
+    any_alert = any(a["alert"] for a in alerts)
+    return {"alert": any_alert, "series": alerts}
+
+
+def _format_alert_text(metrics: dict, decision: dict) -> str:
+    lines = [
+        f"Halacha quality alert — window={metrics['window_days']}d",
+        "",
+    ]
+    for s in decision["series"]:
+        sym = "ALERT" if s["alert"] else "ok"
+        baseline = f"{s['baseline']:.3f}" if s["baseline"] is not None else "—"
+        recent = f"{s['recent']:.3f}" if s["recent"] is not None else "—"
+        drift = f"{s['drift']:.1%}" if s["drift"] is not None else "—"
+        lines.append(
+            f"  [{sym}] {s['series']}: baseline={baseline} recent={recent} "
+            f"drift={drift} n={s['recent_n']}"
+        )
+        if s["reason"]:
+            lines.append(f"          {s['reason']}")
+    return "\n".join(lines)
+
+
+async def run(
+    *,
+    window_days: int,
+    threshold: float,
+    min_sample: int,
+) -> dict:
+    metrics = await _collect_metrics(window_days)
+    decision = _evaluate(metrics, threshold, min_sample)
+    return {
+        "generated_at": datetime.now(timezone.utc).isoformat(),
+        "window_days": window_days,
+        "threshold_rel": threshold,
+        "min_sample": min_sample,
+        "metrics": metrics,
+        "decision": decision,
+    }
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Monitor halacha extraction quality (confidence drift)."
+    )
+    parser.add_argument(
+        "--window", type=int, default=7,
+        help="Recent window in days (default: 7).",
+    )
+    parser.add_argument(
+        "--threshold", type=float, default=0.05,
+        help="Relative drop alert threshold (default: 0.05 = 5%%).",
+    )
+    parser.add_argument(
+        "--min-sample", type=int, default=5,
+        help="Minimum halachot in window to evaluate (default: 5). "
+             "Below this, the series is reported but not alerted on.",
+    )
+    parser.add_argument(
+        "--silent", action="store_true",
+        help="Suppress stderr alert text; only print JSON.",
+    )
+    parser.add_argument(
+        "--exit-on-alert", action="store_true",
+        help="Exit with status 1 when an alert fires (default: always exit 0).",
+    )
+    args = parser.parse_args()
+
+    report = asyncio.run(
+        run(
+            window_days=args.window,
+            threshold=args.threshold,
+            min_sample=args.min_sample,
+        )
+    )
+
+    # JSON to stdout
+    print(json.dumps(report, ensure_ascii=False, indent=2))
+
+    if report["decision"]["alert"] and not args.silent:
+        print("", file=sys.stderr)
+        print(_format_alert_text(report["metrics"], report["decision"]), file=sys.stderr)
+
+    if args.exit_on_alert and report["decision"]["alert"]:
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()