feat(check): 文件要在、扫描件兜底（C10）；响应方式存进清单并可改（C12）

- check/presence.py：「提供《授权委托书》」「须提交投标函」这类要求按标题里有没有这个文件名判断，不调模型。
- 扫描件兜底：要附证明材料的要求没找到、投标文件里有扫描件页时，改为提示级「可能在扫描件里，请人工核对」。
- 响应方式解析时识别、带依据句子存进 checklist.response_modes（迁移 0008）；清单页显示、可改（写审计，
  重新解析不覆盖人工改过的）；查标用存下来的。新接口 PUT /projects/{id}/checklist/response-modes/{category}。
- check_item_result.layer 加 presence（迁移 0007）；契约同步默认接受的两种结论。

开发集 17 份：规矩投标文件的致命问题 120 → 51，致命级召回不变（22 / 32）（docs/architecture/check-eval.md §5）。

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/architecture/openapi.yaml

@@ -1171,6 +1171,34 @@ paths:
           description: '`checklist_empty` 或 `project_read_only`'
           content: { application/problem+json: { schema: { $ref: '#/components/schemas/Problem' } } }
 
+  /projects/{project_id}/checklist/response-modes/{category}:
+    parameters:
+      - $ref: '#/components/parameters/ProjectId'
+      - name: category
+        in: path
+        required: true
+        schema: { type: string, enum: [technical, commercial] }
+    put:
+      tags: [checklist]
+      operationId: setResponseMode
+      summary: 改招标文件某一类要求的响应方式（C12 的人工确认点）
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              type: object
+              required: [mode]
+              properties:
+                mode: { type: string, enum: [explicit, implicit] }
+      responses:
+        '200':
+          description: 返回清单概况
+          content:
+            application/json:
+              schema: { $ref: '#/components/schemas/Checklist' }
+        '409': { $ref: '#/components/responses/ProjectReadOnly' }
+
   /projects/{project_id}/checklist/versions:
     parameters:
       - $ref: '#/components/parameters/ProjectId'
@@ -2469,6 +2497,10 @@ components:
       type: object
       required: [status, version_no, counts, marking_rules]
       properties:
+        response_modes:
+          type: array
+          description: 招标文件对技术、商务要求的响应方式（C12）。识别出来的（origin = rule）可以改（origin = human，人工确认点）；查标按它判没找到响应算不算问题
+          items: { $ref: '#/components/schemas/ResponseMode' }
         status: { type: string, enum: [draft, confirmed] }
         version_no: { type: integer, description: 最近一次确认的版本号；没确认过为 0 }
         confirmed_by:
@@ -2863,6 +2895,25 @@ components:
           oneOf:
             - $ref: '#/components/schemas/Timestamp'
             - type: 'null'
+    ResponseMode:
+      type: object
+      required: [category, mode, status, origin, citations]
+      properties:
+        category: { type: string, enum: [technical, commercial] }
+        mode: { type: string, enum: [explicit, implicit], description: 逐条响应 / 默认接受（只列偏离） }
+        status: { type: string, enum: [found, conflict, unknown], description: 写明了 / 两处写法冲突（按逐条处理）/ 没写明（按逐条处理） }
+        origin: { type: string, enum: [rule, human] }
+        citations:
+          type: array
+          items: { $ref: '#/components/schemas/Citation' }
+        set_by:
+          oneOf:
+            - $ref: '#/components/schemas/UserRef'
+            - type: 'null'
+        set_at:
+          oneOf:
+            - $ref: '#/components/schemas/Timestamp'
+            - type: 'null'
     CheckItemResult:
       type: object
       required: [checklist_item_id, verdict, layer, evidence_status, bid_citations, detail, reused]
@@ -2871,11 +2922,12 @@ components:
         title: { type: [string, 'null'] }
         verdict:
           type: string
-          enum: [responded, not_found, negative_deviation, suspected_unmet, no_value, undetermined, scanned]
+          enum: [responded, not_found, negative_deviation, suspected_unmet, no_value, undetermined, scanned, implicit_accepted, implicit_review]
           description: |
-            已响应 / 未找到 / 负偏离未说明 / 疑似不满足 / 未给出具体值 / 未判定（模型漏答或暂时不可用）/ 扫描件请人工核对。
+            已响应 / 未找到 / 负偏离未说明 / 疑似不满足 / 未给出具体值 / 未判定（模型漏答或暂时不可用）/ 扫描件请人工核对 /
+            按招标文件默认接受（未列入偏离表的视为接受，不出问题）/ 默认接受的实质性要求、请人工核对（C12）。
             没有校验通过的投标侧证据，不会是 responded（架构 §3.6）
-        layer: { type: string, enum: [deviation_table, rule_compare, model, retrieval], description: 结论来自哪一层（m3-plan §2.1） }
+        layer: { type: string, enum: [deviation_table, rule_compare, model, retrieval, presence], description: 结论来自哪一层（m3-plan §2.1；presence 是按文件在不在判断） }
         evidence_status: { type: string, enum: [verified, unverified, none] }
         reason_code: { type: [string, 'null'], description: 证据没通过、漏答、模型错误等的原因码 }
         bid_citations: