重组为 backend/clients/docs 三层结构，并清理 git 污染。

将后端迁入 backend/，完善根目录 .gitignore，删除误提交的 .mypy_cache 缓存文件。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/repositories/voice_audits.py

@@ -0,0 +1,72 @@
+from __future__ import annotations
+
+from datetime import datetime, timezone
+
+from sqlalchemy import func, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.db.models import VoiceConfirmationAudit
+
+
+class VoiceAuditRepository:
+    """Persist voice confirmation audit rows."""
+
+    async def list_by_surgery(
+        self,
+        session: AsyncSession,
+        surgery_id: str,
+        *,
+        limit: int = 50,
+        offset: int = 0,
+    ) -> tuple[list[VoiceConfirmationAudit], int]:
+        """按手术号分页列出审计行，按 `created_at` 降序（新在前）。"""
+        c = (
+            select(func.count())
+            .select_from(VoiceConfirmationAudit)
+            .where(VoiceConfirmationAudit.surgery_id == surgery_id)
+        )
+        total = int((await session.execute(c)).scalar_one())
+        q = (
+            select(VoiceConfirmationAudit)
+            .where(VoiceConfirmationAudit.surgery_id == surgery_id)
+            .order_by(VoiceConfirmationAudit.created_at.desc())
+            .offset(offset)
+            .limit(limit)
+        )
+        rows = list((await session.execute(q)).scalars().all())
+        return rows, total
+
+    async def save_audit(
+        self,
+        session: AsyncSession,
+        *,
+        surgery_id: str,
+        confirmation_id: str,
+        status: str,
+        audio_object_key: str | None,
+        audio_content_type: str | None,
+        audio_size_bytes: int | None,
+        audio_sha256: str | None,
+        asr_text: str | None,
+        resolved_label: str | None,
+        options_snapshot_json: str | None,
+        error_message: str | None,
+        created_at: datetime | None = None,
+    ) -> None:
+        when = created_at or datetime.now(timezone.utc)
+        row = VoiceConfirmationAudit(
+            surgery_id=surgery_id,
+            confirmation_id=confirmation_id,
+            status=status,
+            audio_object_key=audio_object_key,
+            audio_content_type=audio_content_type,
+            audio_size_bytes=audio_size_bytes,
+            audio_sha256=audio_sha256,
+            asr_text=asr_text,
+            resolved_label=resolved_label,
+            options_snapshot_json=options_snapshot_json,
+            error_message=error_message,
+            created_at=when,
+        )
+        session.add(row)
+        await session.flush()