printedparts stage 2: models, real 0001 baseline, tables live

PrintedItem (catalog: code, name, image, cached quantityonhand,
per-item threshold, bin) and PrintedItemTransaction (the ledger:
signed quantity change attributed to a badge-resolved employee).
Both registered in PLUGIN_TABLE_OWNERS; 0001 is a post-cutover real
baseline. The migration-guard test learns the new expected head.
Routes are a placeholder ping until the next stage - the scaffold's
list route imported the deleted scaffold model, which surfaces as an
empty 'Migration error' because the alembic env imports the models
package.

plugins/printedparts/models/__init__.py

@@ -1,5 +1,5 @@
 """Printedparts plugin models."""
 
-from .printedparts import Printedparts
+from .printeditem import PrintedItem, PrintedItemTransaction, TRANSACTION_TYPES
 
-__all__ = ['Printedparts']
+__all__ = ['PrintedItem', 'PrintedItemTransaction', 'TRANSACTION_TYPES']

plugins/printedparts/models/printeditem.py

@@ -0,0 +1,95 @@
+"""Printedparts models.
+
+PrintedItem is a KIND of 3D-printed part with a quantity on hand - a
+consumable, not an ADR-001 asset (which is one row per physical thing).
+PrintedItemTransaction is the ledger: every take, restock, and adjust as a
+signed quantity change attributed to a badge-resolved employee. The ledger is
+the source of truth; quantityonhand is a cache moved in the same commit as
+each ledger write, and the stock report reconciles the two.
+"""
+
+from datetime import datetime, timezone
+
+from shopdb.api import db, BaseModel
+
+
+def _utcnow():
+    return datetime.now(timezone.utc).replace(tzinfo=None)
+
+
+TRANSACTION_TYPES = ('take', 'restock', 'adjust')
+
+
+class PrintedItem(BaseModel):
+    """A printable part the engineers stock in bins."""
+
+    __tablename__ = 'printeditems'
+
+    printeditemid = db.Column(db.Integer, primary_key=True)
+    itemcode = db.Column(db.String(20), unique=True, index=True,
+                         comment='Generated bin-label code, e.g. 3DP-0042')
+    itemname = db.Column(db.String(120), nullable=False)
+    itemdescription = db.Column(db.String(500))
+    imageurl = db.Column(db.String(255))
+    quantityonhand = db.Column(db.Integer, nullable=False, default=0)
+    lowstockthreshold = db.Column(db.Integer, nullable=False, default=5)
+    binlocation = db.Column(db.String(100))
+    printnotes = db.Column(db.Text, comment='Material, print time, slicer file')
+
+    transactions = db.relationship(
+        'PrintedItemTransaction', backref='printeditem',
+        cascade='all, delete-orphan', passive_deletes=True, lazy='dynamic')
+
+    @property
+    def islowstock(self):
+        return self.quantityonhand <= self.lowstockthreshold
+
+    def to_dict(self):
+        return {
+            'printeditemid': self.printeditemid,
+            'itemcode': self.itemcode,
+            'itemname': self.itemname,
+            'itemdescription': self.itemdescription,
+            'imageurl': self.imageurl,
+            'quantityonhand': self.quantityonhand,
+            'lowstockthreshold': self.lowstockthreshold,
+            'islowstock': self.islowstock,
+            'binlocation': self.binlocation,
+            'printnotes': self.printnotes,
+            'isactive': self.isactive,
+            'createddate': self.createddate.isoformat() + 'Z' if self.createddate else None,
+            'modifieddate': self.modifieddate.isoformat() + 'Z' if self.modifieddate else None,
+        }
+
+
+class PrintedItemTransaction(BaseModel):
+    """One signed stock movement, always attributed to an employee."""
+
+    __tablename__ = 'printeditemtransactions'
+
+    transactionid = db.Column(db.Integer, primary_key=True)
+    printeditemid = db.Column(
+        db.Integer,
+        db.ForeignKey('printeditems.printeditemid', ondelete='CASCADE'),
+        nullable=False, index=True)
+    transactiontype = db.Column(db.String(10), nullable=False,
+                                comment='take, restock, or adjust')
+    quantitychange = db.Column(db.Integer, nullable=False,
+                               comment='Negative for take, signed for adjust')
+    employeesso = db.Column(db.String(20), nullable=False, index=True)
+    employeename = db.Column(db.String(120))
+    reason = db.Column(db.String(255))
+    transactiondate = db.Column(db.DateTime, nullable=False, default=_utcnow,
+                                index=True)
+
+    def to_dict(self):
+        return {
+            'transactionid': self.transactionid,
+            'printeditemid': self.printeditemid,
+            'transactiontype': self.transactiontype,
+            'quantitychange': self.quantitychange,
+            'employeesso': self.employeesso,
+            'employeename': self.employeename,
+            'reason': self.reason,
+            'transactiondate': self.transactiondate.isoformat() + 'Z' if self.transactiondate else None,
+        }

plugins/printedparts/models/printedparts.py

@@ -1,32 +0,0 @@
-"""Printedparts model.
-
-This is an Asset extension table keyed by assetid. The Asset row holds
-the platform fields (assetnumber, name, vendorid, locationid, etc.);
-this table holds the printedparts-specific fields. Replace the example fields
-below with your domain model.
-"""
-
-from shopdb.api import db, BaseModel
-
-
-class Printedparts(BaseModel):
-    """Printedparts domain entity, extending Asset by assetid."""
-
-    __tablename__ = 'printedparts'
-
-    assetid = db.Column(
-        db.Integer,
-        db.ForeignKey('assets.assetid', ondelete='CASCADE'),
-        primary_key=True,
-    )
-
-    # TODO: replace these example fields with your domain fields.
-    examplefield = db.Column(db.String(255), nullable=True)
-
-    asset = db.relationship('Asset', backref=db.backref('printedparts', uselist=False))
-
-    def to_dict(self):
-        return {
-            'assetid': self.assetid,
-            'examplefield': self.examplefield,
-        }