Printer assignment end to end, and a container that keeps a site's files

Assign printers to a MACHINE and let whichever PC controls it install them, with
the observed half kept strictly apart from the assigned half: a collector report
can never write an assignment row. Adoption is explicit. Adds a singular
relationship type so defaultprinter can mean exactly one, client scripts that
converge a bay's queues and correct a drifted one in place, and a wave gate so a
fleet-wide driver rollout cannot stampede its own share.

On the container side: the compose stack never persisted the instance directory,
so a rebuild discarded plugins.json and every upload. It is a volume now, the
image ships instance/ owned by the app user so the mountpoint is writable, and
the database moves to MySQL 8.4 LTS, which the Windows runbook has recommended
since 8.0 went end of life. The image also could not build at all: the frontend
stage never copied the plugin staging script it runs.

Adds a topology migration guide covering IIS to Docker and back.

plugins/printers/models/printer_driver.py

@@ -11,6 +11,15 @@ class PrinterDriver(db.Model):
     # SMB path (\\\\server\\share\\...) or HTTP URL to the driver package
     location = db.Column(db.String(500), nullable=False)
     description = db.Column(db.Text)
+    # Exact driver name as the INF declares it: Add-PrinterDriver matches on
+    # this string, not on `name`, which is ours to choose
+    drivername = db.Column(db.String(255))
+    # Optional: attach a driver to a whole VENDOR rather than one model. A
+    # universal driver (HP UPD, Xerox GPD) serves every printer of that make, and
+    # binding it to one model would mean a near-duplicate row per model.
+    # Model wins over vendor when both match - see _printer_driver.
+    vendorid = db.Column(db.Integer, nullable=True, index=True)
+
     # Optional: attach a driver to a specific printer model
     modelnumberid = db.Column(
         db.Integer,
@@ -27,6 +36,8 @@ class PrinterDriver(db.Model):
             'name': self.name,
             'location': self.location,
             'description': self.description,
+            'drivername': self.drivername,
+            'vendorid': self.vendorid,
             'modelnumberid': self.modelnumberid,
             'modelname': self.model.modelnumber if self.model else None,
             'isactive': bool(self.isactive),