fix(jcef): guard zoom shortcut outside desktop

[haizhi03]

Related issue

Closes #2363

Summary

This PR prevents browser development environments from calling JCEF-only zoom APIs when window.javaQuery is
unavailable.

The global zoom shortcuts currently call jcefApi.webFrameSetZoom(...) directly. That API depends on the JCEF bridge
injected by the desktop container. In a normal browser/web development environment, the bridge does not exist, so
pressing a zoom shortcut raises an unhandled rejection: Java Query is not available.

The fix adds a shared JCEF availability check, routes zoom shortcut handling through a small helper, and lets normal
browser environments keep their default zoom behavior instead of intercepting the shortcut.

Affected surfaces

• Frontend / Web
• Backend / API / Storage
• Database plugin / Driver
• JCEF / Desktop packaging
• CI / Build / Release
• Documentation only

Verification

• Commands and results:

  • yarn test:shortcut
    • Passed. Existing shortcut tests passed and the new JCEF zoom regression test passed.
  • yarn eslint src/jcef/base.ts src/utils/shortcutManager.ts src/utils/jcefZoom.ts src/utils/jcefZoom.test.ts --max- warnings=0
    • Passed.

• Manual verification:

  • Verified that zoom shortcut handling now checks whether window.javaQuery is available before calling
    webFrameSetZoom.
  • In non-JCEF/browser environments, the shortcut manager does not intercept zoom shortcuts, so browser default zoom
    behavior can continue.

• UI evidence: N/A

Risk and compatibility

• Public API or stored data:

  • N/A. This change only affects frontend shortcut handling and JCEF bridge availability checks.

• Database or driver compatibility:

  • N/A. No database or driver behavior is changed.

• Network, privacy, or security:

  • N/A. No network requests, credentials, or private data handling are changed.

• Community / Local / Pro boundary:

  • Low risk. The change only skips JCEF-only zoom calls when the JCEF bridge is unavailable.

• Backward compatibility:

  • Desktop/JCEF behavior is preserved when window.javaQuery is available.
  • Browser/web development behavior improves by avoiding an unhandled rejection and preserving default browser zoom
    behavior.

Reviewer map

• Start here:

  • chat2db-community-client/src/utils/shortcutManager.ts
  • chat2db-community-client/src/utils/jcefZoom.ts
  • chat2db-community-client/src/jcef/base.ts

• Failure condition:

  • Pressing zoom shortcuts in a normal browser environment still triggers Unhandled Rejection (Error): Java Query is not available.
  • Pressing zoom shortcuts in the JCEF desktop container no longer calls web-frame-set-zoom.

• Rollback or disable path:

  • Revert this PR to restore the previous direct jcefApi.webFrameSetZoom(...) shortcut behavior.

Contributor declaration

• I linked the Issue that defines this change.
• I tested the affected behavior and reported the actual results above.
• I did not include credentials, private data, or generated build output.
• I disclosed substantial AI assistance below, or this PR contains no substantial AI-generated code.

AI assistance: Used AI assistance to identify the JCEF shortcut guard point, implement the frontend fix, and draft
regression coverage.