feat: extract shared infrastructure from shared_lib

Phase 1-3 of decoupling plan:
- Shared DB, models, infrastructure, browser, config, utils
- Event infrastructure (domain_events outbox, bus, processor)
- Structured logging
- Generic container concept (container_type/container_id)
- Alembic migrations for all schema changes

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

alembic/versions/f6d4a0b2c3e7_add_domain_events_table.py

@@ -0,0 +1,40 @@
+"""add domain_events table
+
+Revision ID: f6d4a0b2c3e7
+Revises: e5c3f9a2b1d6
+Create Date: 2026-02-11
+"""
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+revision = 'f6d4a0b2c3e7'
+down_revision = 'e5c3f9a2b1d6'
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        'domain_events',
+        sa.Column('id', sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column('event_type', sa.String(128), nullable=False),
+        sa.Column('aggregate_type', sa.String(64), nullable=False),
+        sa.Column('aggregate_id', sa.Integer(), nullable=False),
+        sa.Column('payload', postgresql.JSONB(astext_type=sa.Text()), nullable=True),
+        sa.Column('state', sa.String(20), server_default='pending', nullable=False),
+        sa.Column('attempts', sa.Integer(), server_default='0', nullable=False),
+        sa.Column('max_attempts', sa.Integer(), server_default='5', nullable=False),
+        sa.Column('last_error', sa.Text(), nullable=True),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('now()'), nullable=False),
+        sa.Column('processed_at', sa.DateTime(timezone=True), nullable=True),
+        sa.PrimaryKeyConstraint('id'),
+    )
+    op.create_index('ix_domain_events_event_type', 'domain_events', ['event_type'])
+    op.create_index('ix_domain_events_state', 'domain_events', ['state'])
+
+
+def downgrade() -> None:
+    op.drop_index('ix_domain_events_state', table_name='domain_events')
+    op.drop_index('ix_domain_events_event_type', table_name='domain_events')
+    op.drop_table('domain_events')