Summary

• lazy-initialize generated service clients in panel modules so panel evaluation no longer creates TDZ-prone cross-chunk singletons
• split panel components into documented domain chunks with lazy panel-support, while routing static-entry shared code to preloadable app-shared
• keep app-shell panel imports type-only/dynamic and strengthen chunk guard tests

Tradeoff

• app-shared remains on the static app-shell path and is intentionally preloadable
• lazy panel domain chunks and panel-support are excluded from HTML modulepreload/static main imports, reclaiming the feat: eliminate barrel file, split panels into variant-based chunks #3113 split without reintroducing the production startup crash

Validation

• node --test tests/chunk-assignment.test.mjs
• npm run typecheck
• npm run build:full
• production preview smoke at http://127.0.0.1:4173/: HTTP 200, no page errors, hasTdzReferenceError: false
• verified dist/index.html no longer modulepreloads panels-* or panel-support, and the built main chunk has no static from "./panel-support..." import

Fixes #3944