docs: add Claude AI assistant rules and configuration

Add comprehensive rule documentation for AI-assisted development covering
authentication surfaces, outbound-call safety invariants, and other project
conventions to guide Claude's understanding of critical system behaviors.

db/migrations/versions/a1b2c3d4e5f6_users_and_pats.py

@@ -0,0 +1,55 @@
+"""users and personal access tokens
+
+Revision ID: a1b2c3d4e5f6
+Revises: 5187577efc23
+Create Date: 2026-07-22 00:00:00.000000
+
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = 'a1b2c3d4e5f6'
+down_revision: Union[str, None] = '5187577efc23'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table('users',
+    sa.Column('id', sa.String(), nullable=False),
+    sa.Column('name', sa.String(), nullable=False),
+    sa.Column('display_name', sa.String(), nullable=True),
+    sa.Column('email', sa.String(), nullable=True),
+    sa.Column('casdoor_sub', sa.String(), nullable=True),
+    sa.Column('created_at', sa.DateTime(), nullable=True),
+    sa.Column('updated_at', sa.DateTime(), nullable=True),
+    sa.PrimaryKeyConstraint('id'),
+    sa.UniqueConstraint('email'),
+    sa.UniqueConstraint('casdoor_sub')
+    )
+    op.create_table('personal_access_tokens',
+    sa.Column('id', sa.String(), nullable=False),
+    sa.Column('user_id', sa.String(), nullable=False),
+    sa.Column('name', sa.String(), nullable=False),
+    sa.Column('token_hash', sa.String(), nullable=False),
+    sa.Column('token_prefix', sa.String(), nullable=False),
+    sa.Column('created_at', sa.DateTime(), nullable=True),
+    sa.Column('last_used_at', sa.DateTime(), nullable=True),
+    sa.Column('expires_at', sa.DateTime(), nullable=True),
+    sa.Column('revoked_at', sa.DateTime(), nullable=True),
+    sa.ForeignKeyConstraint(['user_id'], ['users.id'], ondelete='CASCADE'),
+    sa.PrimaryKeyConstraint('id'),
+    sa.UniqueConstraint('token_hash')
+    )
+    op.create_index(op.f('ix_personal_access_tokens_token_hash'), 'personal_access_tokens', ['token_hash'], unique=True)
+    op.create_index(op.f('ix_personal_access_tokens_user_id'), 'personal_access_tokens', ['user_id'], unique=False)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f('ix_personal_access_tokens_user_id'), table_name='personal_access_tokens')
+    op.drop_index(op.f('ix_personal_access_tokens_token_hash'), table_name='personal_access_tokens')
+    op.drop_table('personal_access_tokens')
+    op.drop_table('users')