test: 9.5-code review minors (M1 conversion test, M5 no-fingerprint audit test, M2/M4 wording)

- M1: test_goal_branch_via_convert_queued_then_claim actually calls
  server._goal_convert_queued on a queued auto-resumed task before
  claiming, instead of only inserting the post-conversion state.
- M5: test_worker_routing_audit_rows_carry_no_fingerprint drives a
  real run_one with an active policy and asserts worker_routing
  audit rows exist and carry no fingerprint (negative control
  verified: injecting fingerprint into the detail fails it).
- M2: 'all callers' wording tightened to the real counts
  (load_routing_policy: 2 production call sites; evaluate_shadow: 1).
- M4: content_fingerprint docstring now states the fingerprint covers
  the full normalized payload including fallback_models, which the
  router deliberately does not apply (fail-safe direction).
No behaviour change; M3 DESIGN.md edits are outside the repo.

cloud/routing_shadow.py

@@ -71,9 +71,10 @@ def parse_worker_routing_detail(detail):
     9.5-code fail-open 清单：解析失败的行返回 None 后在
     evaluate_shadow 里直接跳过、不计数、不报错——样本无
     声消失（例如模型名含空白会使整行匹配失败，见 M7）。
-    这是已知缺口：改返回类型会牵动评估函数与端点，本轨
-    只在此处写明，不改语义；运营方无法从报告里看到丢
-    了多少行，只能靠审计行总数与样本数对不上来发现。
+    这是已知缺口：改返回类型只需同步评估函数的唯一生产
+    调用方（server 影子端点）与测试，本轨只在此处写明，
+    不改语义；运营方无法从报告里看到丢了多少行，只能靠
+    审计行总数与样本数对不上来发现。
     """
     if not isinstance(detail, str):
         return None