feat(systems): the area vocabulary becomes a global table so a rule can point at one (#3027, milestone 307 step 1)

The eight standard area names already existed — as STANDARD_SYSTEMS, a tuple in
services/systems.py that milestone 297 seeds at inception. A constant cannot be
a foreign key, so nothing outside a project could reference an area: systems.
project_id is NOT NULL, and a rule that spans projects would have to chain
itself to one project's row. And because the list only ever applied on the
inception-seed path, three spellings of one area reached this instance anyway
(CI & runners / CI and Release / CI & release).

- canonical_systems: global, no user_id — a shared project inherits the
  vocabulary instead of re-earning it. Migration 0087 seeds the same eight.
- systems.canonical_id: nullable, SET NULL. Association only — no System is
  renamed and record_systems is untouched, so no record's tags move.
- canonical_slug folds &/and, case and punctuation, so spelling variants map
  mechanically and a real difference ("CI & runners") becomes a proposal a
  human confirms. propose_mappings reports; set_system_canonical is the only
  writer.
- seed_standard_systems now reads the catalog and maps as it mints, so a
  project born standard never needs a reconciliation pass.
- Catalog writes are admin-only; reads are open — a global list anyone can
  extend stops being shared.
- backup: carried by SLUG, not id (ids are per-install). Restore reuses the
  target's own rows and only creates entries an admin added on the source; an
  unknown slug restores unmapped rather than failing.

Rule 22: STANDARD_SYSTEMS is removed, not deprecated. Rule 115: nothing seeded
names an app, repo or house convention. Design in note 3026.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/scribe/services/systems.py

@@ -14,38 +14,39 @@ from scribe.models import async_session
 from scribe.models.note import Note
 from scribe.models.system import RecordSystem, System
 from scribe.services import access
+from scribe.services import canonical_systems as canonical_systems_svc
 
 logger = logging.getLogger(__name__)
 
 
-# The standard cross-project vocabulary (#2798): names that mean the same
-# thing in every project, so a starter set reads the same everywhere. The
-# bootstrap ask (mcp/tools/systems) names them; the inception seed
-# (services/inception, milestone 297) mints them. Charters are deliberately
-# generic — a project refines them as its own records accrue.
-STANDARD_SYSTEMS: tuple[tuple[str, str], ...] = (
-    ("CI & Release", "How the project is verified and shipped: pipelines, runners, image/artifact builds, release tagging and rollback."),
-    ("Auth & Access", "Who may do what: identity, sessions/tokens, permissions and the scoping of every read and write to the right users."),
-    ("Data Model & Storage", "What is stored and how it is shaped: the schema, migrations, serialisation and the services that own a table's lifecycle."),
-    ("API Surface", "The doors into the capability: HTTP routes, tool/RPC surfaces, request parsing, error envelopes and their contracts."),
-    ("UI & Design", "What people see and touch: views, components, client state, and the design tokens/recipes they are built from."),
-    ("Import & Export", "Data crossing the boundary: backups, exports, imports, sync with other systems, file formats."),
-    ("Background Jobs", "Work that runs without a request: schedulers, queues, periodic ticks, retention and maintenance."),
-    ("Observability", "How the system reports on itself: logging, metrics, audit trails, health and diagnostics."),
-)
+async def standard_systems() -> list[tuple[str, str]]:
+    """The standard cross-project vocabulary (#2798) as (name, charter) pairs.
+
+    Reads the GLOBAL canonical catalog (milestone 307). This was a tuple
+    constant in this module until the catalog became a table: a constant
+    cannot be a foreign key, so nothing outside a project could reference an
+    area, and the list only ever applied on the inception-seed path — which is
+    how three spellings of "CI & Release" reached one instance anyway.
+    """
+    return [(entry.name, entry.description or "") for entry in
+            await canonical_systems_svc.list_canonical_systems()]
 
 
 async def seed_standard_systems(user_id: int, project_id: int) -> list[System]:
     """Mint the standard starter set for a project that has NO Systems yet
     (milestone 297). Idempotent: a project with any System — the vocabulary
     already started, standard or not — gets nothing; the duplicate gate and
-    the project's own judgment take it from there. [] without write access."""
+    the project's own judgment take it from there. [] without write access.
+
+    Seeded Systems are mapped to their catalog entry as they are created, so a
+    project born this way needs no reconciliation pass later."""
     if await list_systems(user_id, project_id, include_archived=True):
         return []
     out: list[System] = []
-    for index, (name, charter) in enumerate(STANDARD_SYSTEMS):
+    for index, entry in enumerate(await canonical_systems_svc.list_canonical_systems()):
         system = await create_system(
-            user_id, project_id, name, description=charter, order_index=index,
+            user_id, project_id, entry.name, description=entry.description,
+            order_index=index, canonical_id=entry.id,
         )
         if system is None:
             break
@@ -60,8 +61,14 @@ async def create_system(
     description: str | None = None,
     color: str | None = None,
     order_index: int = 0,
+    canonical_id: int | None = None,
 ) -> System | None:
-    """Create a System. None if the user can't write the project."""
+    """Create a System. None if the user can't write the project.
+
+    `canonical_id` maps the new System onto the global catalog; leaving it None
+    is fine — an unmapped System is fully usable, and the mapping can be
+    proposed later (services/canonical_systems.propose_mappings).
+    """
     if not await access.can_write_project(user_id, project_id):
         return None
     async with async_session() as session:
@@ -72,6 +79,7 @@ async def create_system(
             description=description,
             color=color,
             order_index=order_index,
+            canonical_id=canonical_id,
         )
         session.add(system)
         await session.commit()
@@ -110,6 +118,10 @@ async def list_systems(
 
 async def update_system(user_id: int, system_id: int, **fields: object) -> System | None:
     """Update a System if the user can write its project."""
+    # canonical_id is deliberately NOT settable here: canonical_systems.
+    # set_system_canonical is its single writer, because it also validates the
+    # catalog entry is live. Two entry points onto one column is the drift this
+    # table exists to end.
     allowed = {"name", "description", "color", "status", "order_index"}
     async with async_session() as session:
         system = await session.get(System, system_id)