feat(vault): add locked funds education state

[comzzy-comzzy]

Summary

Resolves issue #265 by enhancing the locked funds education experience across the vault screens and modals.

Changes Made

1. VaultLockEducationModal:

   • Expanded copy to clearly explain:
     • Why funds are locked: Explains that locked funds are set aside securely by the smart contract to promote saving goals and prevent accidental spending.
     • When funds become withdrawable: Details that funds become withdrawable as soon as the unlock date passes, displaying a 'Ready' status badge without any deadline or expiration to claim them.
     • How unlock timing is determined: Explains that unlock timing is established at lock creation and enforced on-chain via network time consensus.
     • Testnet notice: Reinforces that locked funds are currently in testnet preview mode.

2. VaultLockDetail:

   • Updated the inline education card ('How locked funds work') to present bullet points addressing lock rationale, contract-driven unlock timing, and withdrawable rules in plain language.

3. Unit Tests:

   • Added test coverage verifying that all required educational points and interaction handlers render and execute correctly.

Acceptance Criteria Checklist

• Locked funds are explained clearly.
• Unlock timing is described.
• Jargon is avoided.
• Withdrawable timing is visible.
• Content matches contract assumptions.

Closes #265