fix(search,eval): alias-hop injected results carry page_id (contradiction-probe crash)

applyAliasHop injected synthetic SearchResults without page_id (the `as
SearchResult` cast hid the missing field), so listActiveTakesForPages bound
undefined/NaN into ANY($1::int[]) and crashed the whole contradiction probe on
real Postgres. Stamp page_id=page.id at the injection site and add a finite-id
filter in generateIntraPagePairs as a defensive backstop (mirrors hybrid.ts:63).

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

src/core/eval-contradictions/runner.ts

@@ -171,11 +171,19 @@ async function generateIntraPagePairs(
   results: SearchResult[],
 ): Promise<ContradictionPair[]> {
   if (results.length === 0) return [];
-  // Unique page_ids only.
-  const pageIds = Array.from(new Set(results.map((r) => r.page_id)));
+  // Unique, FINITE page_ids only. Defensive backstop for the alias-hop bug
+  // (#2339 sibling): an alias-injected synthetic result with an undefined/NaN
+  // page_id must never reach `ANY($1::int[])` — postgres.js rejects it with
+  // UNDEFINED_VALUE and aborts the whole probe. Mirrors the hybrid.ts:63 filter.
+  const pageIds = Array.from(
+    new Set(
+      results.map((r) => r.page_id).filter((n): n is number => typeof n === 'number' && Number.isFinite(n)),
+    ),
+  );
   const takesByPage = await engine.listActiveTakesForPages(pageIds);
   const out: ContradictionPair[] = [];
   for (const r of results) {
+    if (typeof r.page_id !== 'number' || !Number.isFinite(r.page_id)) continue;
     const takes = takesByPage.get(r.page_id) ?? [];
     if (takes.length === 0) continue;
     const chunkMember = searchResultToMember(r);

src/core/search/hybrid.ts

@@ -647,6 +647,11 @@ export async function applyAliasHop(
     if (!page) continue;
     injectScore += 1e-6;
     out.push({
+      // #2339-sibling: include page_id. The `as SearchResult` cast hid its
+      // absence, so any consumer reading page_id off an alias-injected result got
+      // undefined — e.g. listActiveTakesForPages bound undefined/NaN into
+      // ANY($1::int[]) and crashed the contradiction probe on real Postgres.
+      page_id: page.id,
       slug: page.slug,
       title: page.title,
       type: page.type,