feat: standardize vault lifecycle events

[dangelo352]

Summary

• standardize lifecycle event topics to (event_name, vault_id, creator) while preserving existing event names
• add a typed VaultLifecycleEventData { amount, destination, status } payload for create, validate, release, redirect, and cancel transitions
• add integration tests that assert emitted topics and decoded payloads via env.events()
• document the indexer-facing event schema in docs/EVENTS.md and update src/doc.md

Tests

• cargo test --test events -- --nocapture
• cargo test
• cargo fmt --check
• cargo clippy --all-targets --all-features -- -D warnings
• git diff --check

Closes #224

[1nonlypiece]

appreciate the effort on this — but #224 isn't assigned to you, and we ask contributors to get assigned to an issue before raising a PR. closing as invalid; please claim #224 on the board first, then open it again and we'll take a proper look. https://discord.gg/xvNAvMJf