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/computers/migrations/versions/0001_baseline.py

@@ -1,27 +0,0 @@
-"""computers plugin: baseline schema
-
-Creates every table owned by the computers 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_computers
-Revises:
-Create Date: 2026-05-30
-
-"""
-from shopdb.plugins.alembic_template import create_plugin_tables, drop_plugin_tables
-
-
-revision = '0001_baseline_computers'
-down_revision = None
-branch_labels = None
-depends_on = None
-
-
-def upgrade():
-    create_plugin_tables('computers')
-
-
-def downgrade():
-    drop_plugin_tables('computers')

plugins/computers/migrations/versions/0002_pc_hardware_fields.py

@@ -1,44 +0,0 @@
-"""Add PC hardware make/model + installed-app version string
-
-Adds computers.vendorid + computers.modelnumberid (PCs carry vendor/model like
-equipment) and computerinstalledapps.installedversion (raw version string from
-automated collection, when there is no curated AppVersion). Supports moving the
-PC form and the collector off the legacy Machine model onto the asset/computer
-model (ADR-001).
-
-Revision ID: 0002_pc_hardware
-Revises: 0001_baseline_computers
-Create Date: 2026-06-26
-
-"""
-from alembic import op
-import sqlalchemy as sa
-
-
-revision = '0002_pc_hardware'
-down_revision = '0001_baseline_computers'
-branch_labels = None
-depends_on = None
-
-
-def upgrade():
-    with op.batch_alter_table('computers') as batch_op:
-        batch_op.add_column(sa.Column('vendorid', sa.Integer(), nullable=True))
-        batch_op.add_column(sa.Column('modelnumberid', sa.Integer(), nullable=True))
-        batch_op.create_foreign_key('fk_computers_vendor', 'vendors',
-                                    ['vendorid'], ['vendorid'])
-        batch_op.create_foreign_key('fk_computers_model', 'models',
-                                    ['modelnumberid'], ['modelnumberid'])
-    with op.batch_alter_table('computerinstalledapps') as batch_op:
-        batch_op.add_column(sa.Column('installedversion', sa.String(length=100),
-                                      nullable=True))
-
-
-def downgrade():
-    with op.batch_alter_table('computerinstalledapps') as batch_op:
-        batch_op.drop_column('installedversion')
-    with op.batch_alter_table('computers') as batch_op:
-        batch_op.drop_constraint('fk_computers_model', type_='foreignkey')
-        batch_op.drop_constraint('fk_computers_vendor', type_='foreignkey')
-        batch_op.drop_column('modelnumberid')
-        batch_op.drop_column('vendorid')