fix(core): artifact panel theme (#13186)

fix AI-340, AI-344

#### PR Dependency Tree


* **PR #13186** 👈

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<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

## Summary by CodeRabbit

* **Style**
* Updated the artifact preview panel layout by removing a fixed height
constraint for improved flexibility.
* Refined visual styling of linked document blocks with updated shadow
effects for better aesthetics.

* **New Features**
* Enhanced document preview rendering to respect the current theme,
providing a more consistent visual experience.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->


#### PR Dependency Tree


* **PR #13186** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

packages/frontend/core/src/blocksuite/ai/components/ai-tools/artifact-tool.ts

@@ -34,7 +34,7 @@ export abstract class ArtifactTool<
       padding: 10px 0;
 
       .affine-embed-linked-doc-block {
-        box-shadow: ${unsafeCSSVar('overlayPanelShadow')};
+        box-shadow: ${unsafeCSSVar('buttonShadow')};
         cursor: pointer;
       }
 

packages/frontend/core/src/blocksuite/ai/components/ai-tools/artifacts-preview-panel.ts

@@ -104,10 +104,6 @@ export class ArtifactPreviewPanel extends WithDisposable(ShadowlessElement) {
       color: ${unsafeCSSVarV2('icon/secondary')};
     }
 
-    .artifact-panel-content {
-      height: calc(100% - 52px);
-    }
-
     .artifact-panel-close:hover {
       background-color: ${unsafeCSSVarV2('layer/background/tertiary')};
     }

packages/frontend/core/src/blocksuite/ai/components/ai-tools/doc-compose.ts

@@ -124,6 +124,7 @@ export class DocComposeTool extends ArtifactTool<
             .options=${{
               customHeading: true,
               extensions: getCustomPageEditorBlockSpecs(),
+              theme: this.theme,
             }}
           ></text-renderer>`
         : html`<div class="doc-compose-result-preview-loading">