fix(agent): v2.2.62 — 출력 degeneration 방어

- 재시작 감지: auto-continuation이 "이어쓰기" 대신 답변을 처음부터
  재생성하면 버림 → 분석이 두 번 나오던 문제 제거
- degeneration 정리 패스(cleanDegeneratedOutput): 문자 벽(같은 기호 8개+),
  (Note:…) 메타 노트, Candidate records 내부 지시문 누출,
  (질문 의도:…)/[핵심 확인 질문] 누출, 연속 중복 문단 제거

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/agent.ts

@@ -269,7 +269,7 @@ export class AgentExecutor {
     }
 
     private sanitizeAssistantContent(text: string): string {
-        return text
+        const stripped = text
             .replace(/<rationale>[\s\S]*?<\/rationale>/gi, '')
             .replace(/^\s*\[PROBLEM\][\s\S]*?\[GOAL\][\s\S]*?\[REASONING\][^\n]*(?:\n+|$)/i, '')
             .replace(/^\s*\[PROBLEM\][\s\S]*?(?:\n\s*\n|$)/i, '')
@@ -283,6 +283,54 @@ export class AgentExecutor {
             .replace(/<\|?channel\|?>\s*final\b\s*(?:<\|?message\|?>)?/gi, '')
             .replace(/<\|?(?:end|return|start|message)\|?>/gi, '')
             .trim();
+        return this.cleanDegeneratedOutput(stripped);
+    }
+
+    /**
+     * Contain the blast radius when a small local model degenerates on a long /
+     * near-full context: runaway character walls, leaked English meta-notes,
+     * leaked internal directives, stuttered duplicate paragraphs. This does not
+     * fix the model failure — it just keeps a bad answer readable instead of a
+     * wall of noise.
+     */
+    private cleanDegeneratedOutput(text: string): string {
+        let s = text;
+        // Runaway character walls — 8+ of the same separator. A real markdown rule
+        // is exactly 3 (`---`/`***`/`___`); nothing legitimate repeats a char 8+ times.
+        s = s.replace(/([_=~.*])\1{7,}/g, '');
+        // Leaked English meta-commentary the model narrates about itself.
+        s = s.replace(/\(Note:[^)]*\)/gi, '');
+        // Leaked project-chronicle directive (inline form — the `## ` heading form is stripped elsewhere).
+        s = s.replace(/\n?Candidate records for this discussion[^\n]*/gi, '');
+        // Leaked follow-up-question scaffolding the system prompt forbids.
+        s = s.replace(/\(\s*질문\s*의도\s*[:：][^)]*\)/g, '');
+        s = s.replace(/\[\s*핵심\s*확인\s*질문\s*\]\s*/g, '');
+        // Collapse consecutive duplicate paragraphs (model stutter).
+        const paras = s.split(/\n{2,}/);
+        const deduped: string[] = [];
+        for (const p of paras) {
+            const norm = p.trim().replace(/\s+/g, ' ');
+            const prevNorm = deduped.length ? deduped[deduped.length - 1].trim().replace(/\s+/g, ' ') : '';
+            if (norm && norm === prevNorm) { continue; }
+            deduped.push(p);
+        }
+        return deduped.join('\n\n').replace(/[ \t]+\n/g, '\n').replace(/\n{3,}/g, '\n\n').trim();
+    }
+
+    /**
+     * True when a continuation round restarted the whole answer from the top
+     * instead of continuing it — a small model commonly ignores "continue from
+     * here". Detected by a shared leading prefix with the answer so far.
+     */
+    private isRestartedAnswer(soFar: string, cont: string): boolean {
+        const norm = (x: string) => x.trim().replace(/\s+/g, ' ').toLowerCase();
+        const a = norm(soFar);
+        const b = norm(cont);
+        if (a.length < 40 || b.length < 40) { return false; }
+        let i = 0;
+        const max = Math.min(a.length, b.length, 80);
+        while (i < max && a[i] === b[i]) { i++; }
+        return i >= 12;
     }
 
     private async restoreLastSession() {
@@ -1103,6 +1151,13 @@ export class AgentExecutor {
                             logInfo('Continuation produced no visible text — stopping.', { model: actualModel, round: continuationCount });
                             break;
                         }
+                        // A weak model often ignores "continue from here" and re-generates the
+                        // whole answer from the top. Discard such a restart instead of merging
+                        // it — otherwise the user gets the entire analysis twice.
+                        if (this.isRestartedAnswer(cleaned.visible, ccl.visible)) {
+                            logInfo('Continuation restarted the answer instead of continuing — discarding it.', { model: actualModel, round: continuationCount });
+                            break;
+                        }
                         const before = cleaned.visible;
                         cleaned = { ...cleaned, visible: mergeContinuationParts(cleaned.visible, ccl.visible), wasThoughtOnly: false };
                         lastOutputTokens = estimateTokens(ccl.visible);