Upstream reference-aware and long-running generated UX

[snissn]

Summary

• upstream reference-aware generated CRUD UI, including owned-record preference and resolved relationship labels
• productize shared relation helpers so the microblog demo can consume base runtime patterns instead of carrying all join logic itself
• improve generated media upload UX with clearer long-running processing states, retry support, and submit blocking while uploads are still in flight
• strengthen the generated home shell so collection cards surface relations, indexes, and media/reference capabilities

Issue coverage

This PR is intended to close #73 by addressing the six tracked areas at the generator/runtime/template level:

1. reference-native author/profile UX patterns
2. owned identity flows
3. image/media upload UX
4. long-running operation UX
5. relationship displays
6. collection-level app shell composition

Notes

• This does not introduce a hardcoded microblog app type.
• The microblog demo still has custom pages, but more of its reusable relation logic now lives upstream in the shared template/runtime.

Testing

• pnpm build
• pnpm mocha test/testCliGenerateUi.js
• pnpm mocha test/testCliUploads.js

Closes #73.