Fix collaborative persistence and deterministic publishing

[DavidBabinec]

Summary

• serialize collaboration-aware writes and preserve authoritative roster deletion/undo semantics
• isolate split-selector style declaration bags during site import
• preserve explicit blank reusable-table route bases
• assemble published pages and visual components in deterministic creation order so publish status remains accurate

Verification

• collaboration relay regression suite and related build/lint gates passed for the original fix
• site-import focused regression passed
• reusable-table focused tests: 13/13 passed
• publish regression is red without the fix and green with it; focused publish tests: 6/6 passed
• latest full build, lint, and diff check passed

This is a draft because the branch combines four product defects reproduced while building portable Instatic template packs.