feat(guidance): an operator's ruling lives on the System it governs, and code is read as behaviour, not intent (milestone 444 steps 1-2, #4754 #4755)

A Librarian session contradicted a decision the operator had made 13 days
earlier. The ruling ("retry, then replace, never give up on a book") was
kept only as a quote in a work log, beside a session's reading of it that
capped replacements at 3. Three later sessions built on the reading, and one
carried the cap into an option as a "known cost", which the operator then
approved without being asked about it.

- writing-records.md: "A ruling goes on the System it governs". What a
  ruling is (the operator decided it; a later change could undo it), how it
  differs from a rule, and where it goes: a Rulings section at the end of
  the System description, one line each with who, when and the source
  record. Written the turn the operator decides; holds what is in force,
  not history; a charter line that contradicts a ruling is fixed in the
  same edit.
- using-scribe SKILL.md: reflex 1 says code tells you what a thing does,
  not what was wanted, and a limit read from code is unconfirmed until a
  System's Rulings says otherwise. Reflex 9 points to the ruling section.
- reporting-back: an option that carries existing behaviour says whose call
  it was (the operator's ruling, or a past session's never confirmed); one
  that contradicts a ruling is a Conflict.
- create_system / update_system docstrings: the Rulings section, and that
  description replaces the whole text.
- test_guidance_ownership: three topics pinned to their owners.
- Plugin version minted.

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

src/scribe/mcp/tools/systems.py

@@ -188,6 +188,13 @@ async def create_system(
     charter, not just a label: the description is what tells a later session
     whether a record belongs here.
 
+    The description is also where the operator's RULINGS for the area live:
+    a `Rulings` section at its end, one line per decision the operator made
+    about how this area must behave — the statement, who decided, when, and
+    the record it came from. The description arrives with every record filed
+    under the System, so a ruling there reaches each session working in the
+    area; a quote in a work log reaches one only if a search matches it.
+
     Args:
         project_id: The project this system belongs to (required).
         name: Short label (required).
@@ -303,6 +310,15 @@ async def update_system(
 ) -> dict:
     """Update a System. Only explicitly provided fields change.
 
+    `description` REPLACES the whole text, so read it with get_system first
+    and send it back entire. Recording a RULING — the operator's decision
+    about how this area must behave — is an edit here: add or change its line
+    in the `Rulings` section at the end, in the turn they decide, citing the
+    record it came from. Overturned, the line changes rather than gaining a
+    successor: the section holds what is in force, and the work log keeps the
+    history. If the charter above it contradicts a ruling, fix that sentence
+    in the same edit.
+
     Args:
         status: 'active' or 'archived'. Archive a system to retire it without
             losing history; archived systems hide from default lists.