feat(services): register workflow-native driver keys in field registry

Workflow reconciliation (see previous commit) showed the 20261022
state variable really stores person identity under driver{i}ID /
driver{i}Phonenumber (x2), while the API get_info group keys
(sfzmhm{i}/sjhm{i}) have zero references in any workflow version -
the legacy group read always returned empty for workflow-produced data.

- registry: +4 keys (driver1/2ID, driver1/2Phonenumber) in
  human1/human2 groups, SENSITIVE, documented as synonymous with
  sfzmhm{i}/sjhm{i}; 24 -> 28 specs
- driver{i}License deliberately NOT registered: the sandbox reads
  state.hphm{i} and only renames the output for confirmation prompts -
  it is not a state key, set_info rejects it as unknown (workflow
  never consumes it)
- intentional diff documented: acdhuman1/2 group output now includes
  the driver keys (legacy FastGPT output did not) - fixes the legacy
  'workflow person data unreadable by group' gap; synonym merging
  (driver1ID vs sfzmhm1) deferred pending caller confirmation
- tests: registry size 28, driver keys present with sensitive level,
  License alias excluded

Verified: 230 unit tests

src/services/fields_registry.py

@@ -70,6 +70,21 @@ def _human_fields(index: int) -> list[FieldSpec]:
         FieldSpec(f"sjhm{index}", group, str, True, SensitiveLevel.SENSITIVE, f"{side}手机号码"),
         FieldSpec(f"sjwh{index}", group, str, True, SensitiveLevel.PUBLIC, f"{side}手机文号"),
         FieldSpec(f"csbw{index}", group, str, True, SensitiveLevel.PUBLIC, f"{side}常熟部位/身份标识"),
+        # workflow 原生键（对账发现，见 docs/assignment6-compat.md）：
+        # state 变量中真实读写的人员身份键，与上方 API 契约键同义并存：
+        # driver{i}ID ~= sfzmhm{i}（身份证明号码）、
+        # driver{i}Phonenumber ~= sjhm{i}（手机号码）。
+        # 注意：workflow Code Sandbox 输出的 driver{i}License 是提示词
+        # 输出别名（源数据为 state.hphm{i}），并非 state 键，故不登记——
+        # 对它 set_info 会按未知键拒绝。
+        FieldSpec(
+            f"driver{index}ID", group, str, True, SensitiveLevel.SENSITIVE,
+            f"{side}驾驶员身份证明号码（workflow 原生键，同义 sfzmhm{index}）",
+        ),
+        FieldSpec(
+            f"driver{index}Phonenumber", group, str, True, SensitiveLevel.SENSITIVE,
+            f"{side}驾驶员手机号码（workflow 原生键，同义 sjhm{index}）",
+        ),
     ]