Merge develop into fix/page-template-demo-issues (#45)

Resolve conflicts from the parallel page-embed refactor that landed in develop
via #49:
- page-embed-view.tsx: keep develop's canonical decideEmbedState for the
  cycle/depth/availability guard; keep #45's #39 chrome cleanup (single source
  link, IconFileText fallback) and #40 refresh remount key. Drop #45's now-unused
  isPageEmbedCycle/isPageEmbedTooDeep wiring.
- page-embed-picker.tsx: use develop's excludeHost util; drop #45's duplicate
  filterPageEmbedOptions and its test.
- page-embed-ancestry-context.test.tsx: keep #45's superset suite.
- page-template-access.spec.ts: keep develop's constructor args; update the two
  deleteByReferenceAndSources assertions to the new 4-arg workspace-scoped
  signature introduced by #45 (#36 defense-in-depth).

Full suite green: server 624, client 219, editor-ext 56, mcp 247.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/server/src/database/repos/ai-agent-roles/ai-agent-roles.repo.ts

@@ -132,7 +132,7 @@ export class AiAgentRoleRepo {
  * generated column type is the broad `JsonValue` union, which a concrete object
  * type is not structurally assignable to.
  */
-function jsonbObject(value: ModelConfigValue | undefined) {
+export function jsonbObject(value: ModelConfigValue | undefined) {
   if (value === null || value === undefined || Object.keys(value).length === 0) {
     return null;
   }