Consolidate bundled plugin schema into the core migration chain

The core chain already owns and reproduces the full bundled schema (deploys run
`flask db upgrade` only). The per-plugin Alembic baselines duplicated those
tables, so `flask plugin upgrade-all` would conflict - a footgun. Remove the 6
bundled plugin migration dirs; the per-plugin Alembic helpers
(alembic_template, PluginMigrationRunner) remain for external/filesystem
plugins. upgrade-all now cleanly no-ops for bundled plugins.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

plugins/usb/migrations/alembic.ini

@@ -1,30 +0,0 @@
-[alembic]
-script_location = .
-prepend_sys_path = .
-file_template = %%(rev)s_%%(slug)s
-
-[logging]
-keys = root
-
-[loggers]
-keys = root
-
-[handlers]
-keys = console
-
-[formatters]
-keys = generic
-
-[logger_root]
-level = INFO
-handlers = console
-qualname =
-
-[handler_console]
-class = StreamHandler
-args = (sys.stderr,)
-level = INFO
-formatter = generic
-
-[formatter_generic]
-format = %%(levelname)-5.5s [%%(name)s] %%(message)s

plugins/usb/migrations/env.py

@@ -1,12 +0,0 @@
-"""Alembic env.py for the usb plugin.
-
-Thin shim that sets PLUGIN_NAME then delegates to the shared template at
-shopdb.plugins.alembic_template, which filters MetaData to only this
-plugin's tables and runs Alembic against the Flask app's engine.
-"""
-import os
-os.environ['PLUGIN_NAME'] = 'usb'
-
-from shopdb.plugins.alembic_template import run_migrations
-
-run_migrations()

plugins/usb/migrations/script.py.mako

@@ -1,23 +0,0 @@
-"""${message}
-
-Revision ID: ${up_revision}
-Revises: ${down_revision | comma,n}
-Create Date: ${create_date}
-
-"""
-from alembic import op
-import sqlalchemy as sa
-${imports if imports else ""}
-
-revision = ${repr(up_revision)}
-down_revision = ${repr(down_revision)}
-branch_labels = ${repr(branch_labels)}
-depends_on = ${repr(depends_on)}
-
-
-def upgrade():
-    ${upgrades if upgrades else "pass"}
-
-
-def downgrade():
-    ${downgrades if downgrades else "pass"}

plugins/usb/migrations/versions/0001_baseline.py

@@ -1,27 +0,0 @@
-"""usb plugin: baseline schema
-
-Creates every table owned by the usb plugin per
-shopdb.plugins.alembic_template.PLUGIN_TABLE_OWNERS. The table definitions
-are derived from the SQLAlchemy models at migration runtime so this stays
-in lockstep with the model layer without duplication.
-
-Revision ID: 0001_baseline_usb
-Revises:
-Create Date: 2026-05-30
-
-"""
-from shopdb.plugins.alembic_template import create_plugin_tables, drop_plugin_tables
-
-
-revision = '0001_baseline_usb'
-down_revision = None
-branch_labels = None
-depends_on = None
-
-
-def upgrade():
-    create_plugin_tables('usb')
-
-
-def downgrade():
-    drop_plugin_tables('usb')