Complete Phase 87 web refactor

[Cyber-preacher]

Summary

Completes the Phase 87 web refactor.

• Splits repeated proposal, veto, chamber, feed, faction, human-node, profile, and My Governance UI logic into named helper modules with focused tests.
• Reorganizes page support files into clearer components, hooks, and proposal-domain folders.
• Splits faction API calls and command posting out of the oversized apiClient.ts while keeping the public API client facade stable.
• Keeps product behavior and DTO shape stable; this is a behavior-preserving refactor.

Validation

• yarn typecheck
• yarn test - 25 files, 102 tests
• yarn build
• git diff --check