feat(work-orders): Add create expense from work order (Story 11.7)

[daveharmswebdev]

Summary

• Add "Create Expense" dialog on work order detail page for quick expense logging without navigation
• Single API call (POST /api/v1/expenses with workOrderId) — simpler than reverse Story 11.6
• Pre-populates property (locked) and category (editable) from work order context
• 38 new unit tests (2,257 total), 0 failures

Test plan

• Verify "Create Expense" button appears in Linked Expenses section on work order detail
• Open dialog and confirm property name + work order description shown read-only
• Create expense with amount, date, category — confirm snackbar and list refresh
• Cancel dialog — confirm no expense created
• Validation: empty amount, zero amount, missing category all show errors
• Error handling: simulate network failure — dialog stays open for retry
• Create multiple expenses for same work order — dialog resets between submissions

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