fix: handle OpenAI-style router responses + log unparseable model output

The router's response shape varies by upstream: some backends return
.message.content, some choices[0].message.content, some only top-level
.content. Prefer them in that order. Record the actually-served model
(_shre.model) in the ledger and log a snippet of unparseable output for
diagnosis.

Co-Authored-By: Claude Fable 5 <[email protected]>

src/lib/review.js

@@ -55,18 +55,22 @@ export async function runReview({ cfg, gitea, db, job, withGlobal, log }) {
   const messages = buildReviewPrompt({
     repo: fullRepo, ref: job.ref, sha, prTitle: job.prTitle, conventions, diff, truncated
   });
-  let review = null, llmError = null;
+  let review = null, llmError = null, servedModel = null;
   await withGlobal(async () => {
     for (let attempt = 1; attempt <= 2; attempt++) {
       try {
-        const content = await chat({
+        const out = await chat({
           routerUrl: cfg.routerUrl, model: cfg.model, messages,
           agentId: 'code-reviewer',
-          sessionId: `review-${owner}-${repo}-${sha.slice(0, 12)}`,
+          sessionId: `review-${owner}-${repo}-${sha.slice(0, 12)}-a${attempt}`,
           tenantId: cfg.tenantId, timeoutMs: cfg.routerTimeoutMs
         });
-        const raw = extractJson(content);
-        if (!raw) throw new Error(`no JSON object in model output (attempt ${attempt})`);
+        servedModel = out.servedModel;
+        const raw = extractJson(out.content);
+        if (!raw) {
+          log(`[${fullRepo}@${sha.slice(0, 8)}] unparseable model output (served=${servedModel}): ${JSON.stringify(out.content.slice(0, 400))}`);
+          throw new Error(`no JSON object in model output (attempt ${attempt})`);
+        }
         review = normalizeReview(raw);
         if (!review) throw new Error('normalization failed');
         llmError = null;
@@ -111,7 +115,7 @@ export async function runReview({ cfg, gitea, db, job, withGlobal, log }) {
     axes: review.axes, overall: review.overall, grade: review.grade,
     verdict: review.verdict, findings: review.findings,
     statusState: state, error: null, diffBytes, truncated,
-    model: cfg.model, durationMs: Date.now() - t0
+    model: servedModel || cfg.model, durationMs: Date.now() - t0
   });
   log(`[${fullRepo}@${sha.slice(0, 8)}] reviewed: ${review.verdict} grade=${review.grade} overall=${review.overall} findings=${review.findings.length} in ${Date.now() - t0}ms`);
   return { ok: true, verdict: review.verdict };

src/lib/router.js

@@ -14,9 +14,14 @@ export async function chat({ routerUrl, model, messages, agentId, sessionId, ten
     throw new Error(`router -> ${res.status}: ${text.slice(0, 300)}`);
   }
   const data = await res.json();
-  const content = data?.message?.content ?? data?.content;
+  // Response shape varies by upstream: prefer .message.content, then
+  // OpenAI-style choices, then top-level .content (which can carry an
+  // upstream-down apology — hence last).
+  const content = data?.message?.content
+    ?? data?.choices?.[0]?.message?.content
+    ?? data?.content;
   if (typeof content !== 'string' || !content.trim()) {
     throw new Error('router returned empty content');
   }
-  return content;
+  return { content, servedModel: data?._shre?.model ?? null };
 }