Title: Add property test for vault claim event emission

[Emmyt24]

Description
Implement a property test proving vault claim operations always emit correct events.

Requirements and context

• Must be secure, tested, and documented where applicable
• Should stay reviewable and fit the current monorepo structure

Suggested execution

• Create branch: add-property-test-for-vault-claim-events
• Keep changes scoped to the issue and reference the task IDs in the PR

Implement changes

• Generate random vault claim scenarios
• Run at least 100 iterations and annotate Property 80
• Assert vlt_cl_v1 event is emitted on success
• Verify event contains correct vault_id, owner, and amount

Test and commit

• Run the most relevant tests for the touched service or UI surface
• Include event schema documentation
• Call out edge cases, assumptions, and any follow-up work

Example commit message

test: add vault claim event emission property

Guidelines

• Prefer small, reviewable PRs
• Keep naming and data contracts consistent with the spec docs
• Preserve responsive and accessible behavior for frontend work

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