feat: typed accounts and transfer events

[aafre]

Summary

• bind imports to typed account IDs with adapter detection, account compatibility checks, and new-account drafts
• add balance provenance/reconciliation gates, canonical signs, semantic import previews, and safe idempotent undo
• classify card payments/refunds/cash withdrawals, persist transfer events, suggest/accept/dismiss/unlink matches, and expose debt/cash analytics
• add account, transfer, import review, and reconciliation API/UI support

Validation

• uv run pytest -q (125 passed)
• uv run ruff check .
• uv run ruff format --check .
• uv run mypy src

Chained on feat/v02-currency-investments.