fix: keep Mermaid diagram edges reachable and add PNG export

Fix oversized diagram alignment in the large-diagram viewer and provide complete PNG downloads independent of zoom and pan. Cover the full window and shared native drag handling, with regression checks for both themes and narrow windows. Validation: 58 focused tests passed, including 9 Electron scenarios and 10 PNG downloads; typecheck and lint passed. Full-suite runs did not complete. Release note: Mermaid 大图放大后可浏览全部边缘，并可从弹窗导出完整 PNG 图片。
2026-09-23 11:53:09 +08:00
parent be84534e77
commit 785b1ee468
14 changed files with 427 additions and 13 deletions
@@ -106,6 +106,8 @@ records are listed separately and do not introduce another feature status.
  stash or discard. Managed SSH operations require Agent `0.11.23`.
 - [x] **Rich responses**: Supports GitHub Flavored Markdown, LaTeX math,
  constrained Mermaid diagrams, and static in-conversation HTML previews.
+  Mermaid's large-diagram viewer keeps all edges reachable when zoomed and
+  exports the complete diagram as PNG, independently of zoom and pan.
  Complete HTML and HTML code blocks can be previewed in place after an Agent
  reply finishes, with icon actions to reveal the source or open a full-screen
  preview. The feature is on by default and can be disabled under Platform