Integration test: txHash retained in synced set after chain-trade delete

[heyitsStylez]

Parent

#68

What to build

A jsdom integration test asserting that after deleteTrade is called on a chain-imported trade, the trade is absent from trades and the txHash is still present in hw_synced_v1.

This locks ADR 0006's invariant as an executable specification so it cannot be accidentally broken by future changes to deleteTrade or the synced-set management.

Prior art: test/integration/chain-sync-outcomes.test.js — boots the full app via setupJsdom(), drives globals, and asserts on localStorage.

Acceptance criteria

• Test file exists under test/integration/
• Test boots the full app via setupJsdom() and calls t.after(teardown)
• Test adds a chain-imported trade (with a txHash) to trades and the txHash to hw_synced_v1
• Test calls deleteTrade(id) on that trade
• Assertion: trade is no longer in trades
• Assertion: txHash is still present in hw_synced_v1
• npm test passes with the new test included

Blocked by

• ADR 0006: document txHash retention on delete #69 (ADR defines the invariant being tested)
• Add edit and delete controls to all holding lot cards #70 (delete button must exist before the behaviour is considered shipped)