## ADDED Requirements

### Requirement: TWAP observations belong to existing filled positions
The service SHALL publish immutable TWAP observations only on matching existing Phoenix positions whose order has a positive actual fill and remaining executions. It SHALL preserve counters, quantities, nullable price and observation/estimated times without UI formatting. No new position SHALL be synthesized. TWAP errors SHALL retain the complete prior venue observation with failure status. Polling frequency SHALL remain unchanged.

#### Scenario: Unfilled order or no position
- **WHEN** an active TWAP has no actual fills or has no matching open position
- **THEN** it is absent from every overview row and cannot create a visible venue

#### Scenario: TWAP read fails
- **WHEN** the TWAP read fails after a successful venue observation
- **THEN** prior positions, TWAP observations and original timestamps remain with failed venue status
- **AND** other venues and wallets continue refreshing