Merge branch 'develop' into feat/ai-chat-review-followups

Integrate the already-merged step-limit work from develop. Only conflict was
ai-chat.service.spec.ts: both sides appended a describe block and edited the
import line. Resolved as a union — keep compactToolOutput + the assistantParts/
serializeSteps/rowToUiMessage suites (this branch) AND the prepareAgentStep
suite (develop), importing all symbols from ai-chat.service.

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

apps/server/src/database/repos/page/page.repo.ts

@@ -672,4 +672,58 @@ export class PageRepo {
         .execute()
     );
   }
+
+  /**
+   * Whole space tree (all root pages and their descendants) in a single
+   * recursive query. Mirrors getPageAndDescendants but seeded by every root
+   * page of the space (parentPageId IS NULL) instead of a single parent.
+   */
+  async getSpaceDescendants(
+    spaceId: string,
+    opts: { includeContent: boolean },
+  ) {
+    return this.db
+      .withRecursive('page_hierarchy', (db) =>
+        db
+          .selectFrom('pages')
+          .select([
+            'id',
+            'slugId',
+            'title',
+            'icon',
+            'position',
+            'parentPageId',
+            'spaceId',
+            'workspaceId',
+            'createdAt',
+            'updatedAt',
+          ])
+          .$if(opts?.includeContent, (qb) => qb.select('content'))
+          .where('spaceId', '=', spaceId)
+          .where('parentPageId', 'is', null)
+          .where('deletedAt', 'is', null)
+          .unionAll((exp) =>
+            exp
+              .selectFrom('pages as p')
+              .select([
+                'p.id',
+                'p.slugId',
+                'p.title',
+                'p.icon',
+                'p.position',
+                'p.parentPageId',
+                'p.spaceId',
+                'p.workspaceId',
+                'p.createdAt',
+                'p.updatedAt',
+              ])
+              .$if(opts?.includeContent, (qb) => qb.select('p.content'))
+              .innerJoin('page_hierarchy as ph', 'p.parentPageId', 'ph.id')
+              .where('p.deletedAt', 'is', null),
+          ),
+      )
+      .selectFrom('page_hierarchy')
+      .selectAll()
+      .execute();
+  }
 }