Phase 7A: wire ADR-001 asset position contract surface

Lock the position-resolution columns from ADR-001 in code so
resolve_asset_position's relationship walk activates.

Schema
- Asset.mapleft -> Asset.mapx, Asset.maptop -> Asset.mapy
- Location.mapx / Location.mapy added (fallback for priority 3 of the
  ADR-001 resolution chain)
- AssetRelationship.label (free-text nuance per ADR-001)
- AssetRelationship.inheritsposition (bool, server_default true, controls
  whether the resolved-position walk follows the edge)
- RelationshipType.propagatesthroughid (self-FK; sibling-propagation rail)

Seeds
- Three canonical ADR-001 relationship types created idempotently:
  partof, controls, connectedto
- controls.propagatesthroughid wired to partof (partof + connectedto stay
  null per ADR-001 table). Both via Alembic migration AND CLI seed command
  so a fresh test fixture and a sister-site deploy both end up correct.
- Legacy connection types (Serial Cable, Direct Ethernet, USB, WiFi,
  Dualpath) retained for backward compat with pre-1.0 relationship rows.

Resolver
- shopdb.api.resolve_asset_position now walks inheritsposition=true edges
  of type partof (then controls), recursively, depth-capped at 3 with
  visited-set cycle protection. Inactive edges + non-inheritable types
  are skipped. Falls through to the existing location fallback when the
  walk yields nothing.

Tests
- 11 new test_api_namespace cases cover: partof walk, controls-after-
  partof ordering, connectedto skipped, inheritsposition=false skipped,
  recursion, cycle break, depth-3 cap, self-beats-related, related-beats-
  location, inactive-edge skip.
- 111 tests pass. Naming/style check green.

Migration
- migrations/versions/7a01_adr001_position_contract.py:
  - alter_column renames on assets (no data loss)
  - add_column on locations + relationshiptypes + assetrelationships
  - idempotent seed of three ADR types + propagation FK wire-up
  - downgrade reverses + best-effort deletion of seeded types that have
    no FK refs

Backend rename (mapleft/maptop -> mapx/mapy)
- shopdb/core/api/assets.py
- plugins/{computers,equipment,network,printers}/api/...
- scripts/migration/migrate_assets.py
- Legacy Machine model + machines API + import_from_mysql.py UNCHANGED
  (per ADR-001 Machine retires; not part of the asset contract)

Frontend rename
- frontend/src/components/ShopFloorMap.vue
- frontend/src/views/{MapEditor.vue, pcs/{PCDetail,PCForm}.vue,
  printers/{PrinterDetail,PrinterForm}.vue,
  machines/{MachineDetail,MachineForm}.vue,
  network/NetworkDeviceForm.vue}
- Form field labels + v-model bindings + computed flags switched in
  lockstep with the backend.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

shopdb/core/models/relationship.py

@@ -5,17 +5,40 @@ from .base import BaseModel
 
 
 class RelationshipType(BaseModel):
-    """Types of relationships between machines/assets."""
+    """
+    Types of relationships between assets.
+
+    ADR-001 seeds three canonical types: partof, controls, connectedto.
+    Sites may add legacy/communication-flavored types (Serial Cable, Direct
+    Ethernet, USB, WiFi, Dualpath) for backward compatibility with pre-1.0
+    data, but new ADR-001 code paths only reason about the three canonical
+    types via free-text label for nuance.
+    """
     __tablename__ = 'relationshiptypes'
 
     relationshiptypeid = db.Column(db.Integer, primary_key=True)
     relationshiptype = db.Column(db.String(50), unique=True, nullable=False)
     description = db.Column(db.Text)
 
-    # Example types:
-    # - "Controls" (PC controls Equipment)
-    # - "Dualpath" (Redundant path partner)
-    # - "Backup" (Backup machine)
+    # Sibling propagation (ADR-001): when a relationship of this type is
+    # created/deleted, the framework finds all assets related to the source
+    # via the type at propagatesthroughid and mirrors the change. Null means
+    # no propagation. Seeded values:
+    #   partof       -> null (propagation rail itself)
+    #   controls     -> partof (controls propagates across siblings)
+    #   connectedto  -> null (network paths don't propagate)
+    propagatesthroughid = db.Column(
+        db.Integer,
+        db.ForeignKey('relationshiptypes.relationshiptypeid'),
+        nullable=True,
+        comment='Sibling-propagation rail per ADR-001'
+    )
+
+    propagatesthrough = db.relationship(
+        'RelationshipType',
+        remote_side=[relationshiptypeid],
+        foreign_keys=[propagatesthroughid],
+    )
 
     def __repr__(self):
         return f"<RelationshipType {self.relationshiptype}>"
@@ -50,9 +73,23 @@ class AssetRelationship(BaseModel):
         nullable=False
     )
 
+    # Free-text description carrying domain nuance ("DNC feed",
+    # "operator workstation", "ethernet PoE"). Avoids inflating type list.
+    label = db.Column(db.String(200), comment='Free-text relationship description (ADR-001)')
+
+    # When true, resolve_asset_position walks across this edge (priority 2
+    # in the resolution chain). Defaults to true for partof + controls when
+    # the relationship is created via the API; nullable for legacy rows.
+    inheritsposition = db.Column(
+        db.Boolean,
+        default=True,
+        nullable=False,
+        server_default='1',
+        comment='If true, resolved-position walk follows this edge (ADR-001)'
+    )
+
     notes = db.Column(db.Text)
 
-    # Relationships
     sourceasset = db.relationship(
         'Asset',
         foreign_keys=[sourceassetid],