docs(plugin): the instruction surfaces teach moments - reading a line that arrived at one, correcting a misfire, and giving a new rule its moments (milestone 458 step 8, #4926)

Until now only the tool arguments knew moments existed. The guidance
surfaces described rules as reached by resemblance alone:

- using-scribe: a short reflex paragraph and a new reference file,
  moments.md. It covers reading "at <moment>, reached by <action>", the
  reply held once at reply.report, map_action / unmap_action offered in
  one line, and the step 7 proposal line answered with judge_rule_moments.
- writing-records: asks WHEN a rule applies as well as what it is about.
  A rule, preference or process about a point in the work gets
  moments=[...] as it is written, and the trigger stays as the net.
- missed-retrieval: a missed WHEN is mounted or mapped, not reworded. A
  misfire is unmounted or unmapped.
- _INSTRUCTIONS: one clause (list_moments; mount rules about WHEN),
  1594 of 1600 chars.
- static context: injected lines include the rules mounted on a moment
  that was reached.
- test_guidance_ownership: three owned topics, so the text cannot quietly
  drop out.

Plugin minted.

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

src/scribe/mcp/server.py

@@ -43,14 +43,15 @@ from quart import Quart
 # decision #4027 and the notes it supersedes.
 _INSTRUCTIONS = """
 Scribe is the operator's system of record, and yours: recall before acting,
-record as you go, keep one copy here rather than in local memory files. Each
-practice below is stated in full in the using-scribe skill (if your client
-reads Agent Skills) and in each tool's description.
+record as you go, keep one copy here, not in local memory files. Each
+practice is stated in full in the using-scribe skill and each tool's
+description.
 
 - Start with enter_project(id): the project, open work, Systems and design
   system. An `inception` key: ask what it inherits, then
   decide_project_inception.
-- Rules are not preloaded; one arrives when your work matches it. Before a
+- Rules are not preloaded; one arrives when your work matches it or reaches
+  a moment it is mounted on (list_moments; mount rules about WHEN). Before a
   consequential act, what_might_apply("what you are about to do");
   search(content_type="rule") reads one you suspect. Silence means nothing
   matched, not none. Rules bind; preferences guide and you keep them current;