fix(balancer): align std example with active release

[makemake-kbo]

Summary

• restore Balancer V3 Vault trigger registration to match active Release 1
• re-enable the existing E2E behavior tests
• remove only the obsolete quarantine notice from the Balancer example README
• match the exact assertion sources synced to the standalone Balancer repository at commit 9e35a899c773b2b1a8910474ca3b0d681dc9446f

Verification

• exact live assertion IDs reproduced from creation bytecode and constructor arguments
• FOUNDRY_PROFILE=balancer pcl test: 42 passed, 0 failed
• forge fmt --check
• git diff --check

[lean-apple]

can you check if we should we fix in this pr safe guard or in another one ?