docs(6205): last id-less stories in services — a ported-from project name and two "this milestone" references

backup_s3 says what its signing is checked against instead of which of the
operator's projects it was ported from; rulebooks and shape_check state what
the code is for rather than which milestone it belonged to.

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

src/scribe/services/rulebooks.py

@@ -324,8 +324,8 @@ def rule_brief(rule: Rule, **extra) -> dict:
     of payload for a precision nobody reads.
 
     `why` and `how_to_apply` are deliberately NOT here — they are the depth a
-    caller gets from get_rule, and putting them in every listing is the bloat
-    this milestone is about.
+    caller gets from get_rule, and putting them in every listing would bloat
+    every payload that lists rules.
     """
     out = {
         "id": rule.id,
@@ -1583,11 +1583,10 @@ async def rules_due_for_verification(
 ) -> list[Rule]:
     """Rules that carry a check, oldest verification first, never-checked top.
 
-    THE QUERY THIS MILESTONE EXISTS FOR. `verify_with` and `expires_when` are
-    storage; this is what turns them into something that gets acted on. The
-    307 audit cost a session and found four broken rules by luck — this makes
-    the same question a list, and staleness measurable by age instead of
-    discoverable by accident.
+    `verify_with` and `expires_when` are storage; this is what turns them into
+    something that gets acted on. Without it, finding broken rules takes an
+    audit and luck — this makes the same question a list, and staleness
+    measurable by age instead of discoverable by accident.
 
     Ordered `verified_at` ASC NULLS FIRST: never-checked outranks
     checked-long-ago, because a rule nobody has ever confirmed is a claim