Phase 6: HITL review endpoints + audit trail

- New job_corrections table (append-only audit log) + migration
- Add approved / reviewed_by / reviewed_at columns to jobs
- PATCH  /documents/{id}         apply field-level corrections
- GET    /documents/{id}/history return chronological audit trail
- POST   /documents/{id}/approve lock final version (idempotent)
- Dotted field-path applier with root allow-list + list-index support
- Auto-clear `missing_field` review flag when required header keys filled
- Atomic batch apply: malformed path in batch rolls back all changes
- 22 new tests (11 repository-level, 11 API-level); 184 total passing

Co-Authored-By: adrian kuman firmansah <adriancuman@gmail.com>

src/ocr_sprint/schemas/review.py

@@ -0,0 +1,62 @@
+"""Request / response schemas for the HITL review endpoints (Phase 6).
+
+The API surface is deliberately small:
+
+* ``CorrectionRequest`` — body of ``PATCH /documents/{id}``. A list of
+  ``FieldCorrection`` entries; each one is applied atomically (all-or-
+  nothing) and recorded in the audit trail.
+* ``CorrectionEventResponse`` — single row in ``GET /documents/{id}/history``.
+* ``ApprovalResponse`` — echo back after ``POST /documents/{id}/approve``.
+"""
+
+from __future__ import annotations
+
+from datetime import datetime
+from typing import Any
+from uuid import UUID
+
+from pydantic import BaseModel, Field
+
+
+class FieldCorrection(BaseModel):
+    """One field-level correction.
+
+    ``path`` is a dotted JSON path into ``ExtractionResult``. Supported
+    roots: ``header``, ``ttd``, ``personel[n]`` (n is a 0-based index),
+    ``untuk``. The path is validated by the repository before being
+    applied; unknown roots return 400.
+    """
+
+    path: str = Field(..., description="Dotted JSON path, e.g. 'header.nomor_sprint'.")
+    value: Any = Field(..., description="New value (any JSON-serialisable payload).")
+    reason: str | None = Field(
+        None, max_length=512, description="Optional free-form reason for the correction."
+    )
+
+
+class CorrectionRequest(BaseModel):
+    """PATCH body — one or more field corrections, applied atomically."""
+
+    corrections: list[FieldCorrection] = Field(..., min_length=1)
+
+
+class CorrectionEventResponse(BaseModel):
+    """One row of the audit log surfaced by GET /history."""
+
+    id: int
+    job_id: UUID
+    field_path: str
+    old_value: Any | None = None
+    new_value: Any | None = None
+    corrected_by: str | None = None
+    reason: str | None = None
+    corrected_at: datetime
+
+
+class ApprovalResponse(BaseModel):
+    """Echo returned after a job is approved."""
+
+    job_id: UUID
+    approved: bool
+    reviewed_by: str | None = None
+    reviewed_at: datetime | None = None