docs(6206): rulebook model comments state the design, not the history of the rulebook

The relation kinds say what each prevents without the rule-46 split story;
the removed tier, subscriptions and suppressions are stated as what the
model does not have, with the migration that dropped them.

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

src/scribe/models/rulebook.py

@@ -92,15 +92,13 @@ class Rule(Base, TimestampMixin, SoftDeleteMixin):
     # WHEN this rule applies — the trigger, not the instruction. Required of
     # new rules at the service layer and nullable here, because rules written
     # before migration 0088 have none and a migration cannot invent one.
-    # It carries three jobs at once (note 3026): it is the readable form of
-    # the canon tag, the half of the document that makes a rule findable by
-    # meaning, and — since milestone 394 removed the always-on tier — the ONLY
-    # thing that decides whether a rule ever reaches a session at all. A rule
+    # It carries three jobs at once: it is the readable form of the canon tag,
+    # the half of the document that makes a rule findable by meaning, and —
+    # with no always-on tier — the ONLY thing that decides whether a rule ever reaches a session at all. A rule
     # with no trigger is not a quiet rule, it is an unreachable one.
     when_to_apply: Mapped[str | None] = mapped_column(Text, nullable=True)
-    # WHAT KIND of instruction this is. `tier` used to sit beside this and
-    # carry delivery; milestone 394 removed it, so kind is now the only axis
-    # on a rule and delivery belongs entirely to retrieval.
+    # WHAT KIND of instruction this is — the only axis on a rule; delivery
+    # belongs entirely to retrieval.
     # `rule` must be FOLLOWED: ignoring it breaks something or crosses a
     # boundary. `preference` is how this person wants work DONE: ignoring it
     # costs consistency, not correctness.
@@ -116,7 +114,7 @@ class Rule(Base, TimestampMixin, SoftDeleteMixin):
     # trigger-dominated document, ownership-scoped search, the retrieval arms,
     # relations, and `rule_versions`, which is where its drift is recorded.
     # Defaults to `rule` so nothing changes force on upgrade.
-    # CHECK ck_rules_kind (migration 0098, rule 36).
+    # CHECK ck_rules_kind (migration 0098).
     kind: Mapped[str] = mapped_column(Text, default="rule", server_default="rule")
     why: Mapped[str | None] = mapped_column(Text, nullable=True)
     how_to_apply: Mapped[str | None] = mapped_column(Text, nullable=True)
@@ -141,7 +139,7 @@ class Rule(Base, TimestampMixin, SoftDeleteMixin):
         DateTime(timezone=True), nullable=True
     )
     # The record that caused this rule — the edge notes and tasks already
-    # have. Rule 46's `why` names note 2813 in prose; this is that link as a
+    # have. A `why` can name its origin in prose; this is that link as a
     # field, so it survives a rewording of the paragraph.
     arose_from_id: Mapped[int | None] = mapped_column(
         BigInteger, ForeignKey("notes.id", ondelete="SET NULL"), nullable=True
@@ -175,10 +173,9 @@ class Rule(Base, TimestampMixin, SoftDeleteMixin):
         }
 
 
-# Which global AREA a rule is about (milestone 307). Points at the canonical
-# catalog, NEVER at a project's `systems` row: a rule that spans projects
-# cannot be chained to one project's vocabulary. This is the edge three
-# projects were drawing by hand, as rule text copied into a System's charter.
+# Which global AREA a rule is about. Points at the canonical catalog, NEVER at
+# a project's `systems` row: a rule that spans projects cannot be chained to
+# one project's vocabulary.
 rule_systems = Table(
     "rule_systems",
     Base.metadata,
@@ -188,7 +185,7 @@ rule_systems = Table(
 )
 
 
-# Which MOMENTS of work a rule arrives at (milestone 458). A rule mounted on a
+# Which MOMENTS of work a rule arrives at. A rule mounted on a
 # moment is delivered whenever that moment happens, by lookup and with no
 # score — the route for a rule that is about WHEN something is done rather
 # than what it is about, which semantic retrieval structurally misses. The
@@ -204,17 +201,15 @@ rule_moments = Table(
 )
 
 class RuleRelation(Base, CreatedAtMixin):
-    """A typed edge between two rules. Each kind exists because its ABSENCE
-    forced a workaround somewhere in the operator's rulebook (note 3026).
+    """A typed edge between two rules. Each kind exists because without it a
+    rulebook needs a workaround.
 
     - ``co_surfaces`` — these fail together, so they must arrive together.
-      Without it, the only way to guarantee that was to merge them into one
-      row, which is what happened to rule 46: split into 144, folded back the
-      same day because "either rule could surface without the other."
+      Without it, the only way to guarantee that is to merge them into one
+      row, because either rule could surface without the other.
       Symmetric in meaning; stored once and read both ways.
-    - ``overrides`` — this rule supersedes that one for its scope. Only
-      *suppression* existed, so an override had to be written as a parallel
-      rule that then drifts from its parent.
+    - ``overrides`` — this rule supersedes that one for its scope. Without
+      it, an override is a parallel rule that drifts from its parent.
     - ``elaborates`` — this rule adds local specifics to that one; surfacing
       the parent brings the addendum with it.
 
@@ -232,7 +227,7 @@ class RuleRelation(Base, CreatedAtMixin):
     to_rule_id: Mapped[int] = mapped_column(
         BigInteger, ForeignKey("rules.id", ondelete="CASCADE"), index=True
     )
-    # CHECK ck_rule_relations_kind (migration 0088, rule 36).
+    # CHECK ck_rule_relations_kind (migration 0088).
     kind: Mapped[str] = mapped_column(Text)
     note: Mapped[str | None] = mapped_column(Text, nullable=True)
 
@@ -251,10 +246,8 @@ class RuleRelation(Base, CreatedAtMixin):
         }
 
 
-# `project_rulebook_subscriptions`, `project_rule_suppressions` and
-# `project_topic_suppressions` lived here until milestone 414 (migration 0101).
-# A rule's home is its scope now: a rule in a rulebook topic is global, a rule
-# on a project applies to that project, and retrieval reads that directly. A
-# subscription had stopped changing anything a session received, and a
-# suppression muted rules from a subscription. A project that departs from a
-# global rule writes a project rule with an `overrides` relation instead.
+# A rule's home is its scope: a rule in a rulebook topic is global, a rule on
+# a project applies to that project, and retrieval reads that directly. There
+# are no per-project subscriptions or suppressions (migration 0101 dropped
+# those tables); a project that departs from a global rule writes a project
+# rule with an `overrides` relation.