feat(integrations): open banking — financial transactions as activities

[diogobaltazar]

Description

Connect Move37 to the user's bank via Open Banking (e.g. TrueLayer, Plaid, or a compatible PSD2 provider). Each incoming financial transaction is ingested as an activity node — a parentless star in the graph (#39). The user can then associate a transaction activity with an existing task, at which point that task gains a dependency on the transaction activity, making the financial behaviour visible as a precondition or correlate of deliberate work.

The design premise: spending is behaviour, and behaviour should be accounted for. If you spent money on something, that transaction should have a home in your activity graph — either as a named, intentional act, or as an unattributed star that quietly asks to be claimed.

How it works

1. Connect: User authenticates with their bank via an Open Banking OAuth flow in the settings pane. Credentials are stored server-side; only transactions are surfaced to the client.
2. Ingest: Transactions sync periodically (or on demand). Each transaction becomes an activity node with metadata: merchant, amount, currency, date.
3. Default placement: Unassociated transactions appear as parentless stars in the stellar field (per feat(graph): notes render as parentless stars in the stellar field #39) — visible but unclaimed.
4. Association: The user can drag or link a transaction star to an existing task node. This creates a dependency edge: the task depends on the transaction activity. The transaction star moves to the appropriate position in the graph.
5. Prompt: Unassociated transaction stars serve as a visual prompt — the constellation of unattributed spending is always visible, inviting the user to reflect and assign intent.

Acceptance criteria

• User can connect and disconnect a bank account via Open Banking OAuth in the settings pane.
• Transactions are fetched and stored as activity nodes with merchant, amount, currency, and date.
• Unassociated transactions render as parentless stars in the stellar field.
• User can associate a transaction with an existing task; this creates a depends-on edge and repositions the node accordingly.
• Disconnecting the bank account stops sync; existing transaction nodes are retained but marked as unsynced.
• No transaction data is sent to third parties beyond the Open Banking provider.

Dependencies

• feat(graph): notes render as parentless stars in the stellar field #39 (parentless star nodes) for the default unassociated rendering.
• Open Banking provider TBD (TrueLayer and Plaid are candidates; provider should be configurable).