fix: apply CEI ordering to governance votes

[sirakinb]

Summary

• persist locked-token, vote, has-voted, and proposal tally effects before locking governance tokens
• keep validation and balance checks before state changes
• move the token transfer after vote effects so callbacks cannot observe the voter as still eligible

Tests

• cargo +1.91.1 test -p pulsar-governance-dao cast_vote
• cargo +1.91.1 test -p pulsar-governance-dao double_vote

Note: cargo fmt -p pulsar-governance-dao --check is currently blocked by pre-existing formatting drift in contracts/governance-dao/src/test.rs; this PR only changes src/lib.rs.

Refs #554

[sirakinb]

Rebased this branch onto current main and kept the governance vote transfer after the vote guard, locked-token record, tally update, and proposal write.

Verification after rebase:

• git diff --check
• cargo +1.91.1 test -p pulsar-governance-dao cast_vote (3 passed)
• cargo +1.91.1 test -p pulsar-governance-dao double_vote (2 passed)

Note: cargo +1.91.1 fmt -p pulsar-governance-dao --check still reports pre-existing formatting drift in contracts/governance-dao/src/test.rs; this branch only changes src/lib.rs.