fix(workspace): keep left panel selection manual

[openai0229]

Related issue

Closes #1974

Summary

Keep the Files and Data Browser left-panel selection under explicit user control.

• Active Console tabs expose both Files/Active Sessions and Data Browser location targets without switching the selected panel.
• Local file tabs locate only in Files, while database-object tabs locate only in Data Browser.
• Manually selecting Files or Data Browser locates the active tab in that panel.
• Clear a Files search when it hides the active Console so the session can be scrolled into view.
• Remove the previous automatic-follow and per-tab manual-override state.

Affected surfaces

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

Verification

• Commands and results:
  • yarn lint - passed.
  • yarn test:i18n - passed.
  • yarn test:active-tab-locator - passed.
  • yarn build:web:community --app_version=0.0.0 - passed; Webpack compiled successfully in 18.07s.
  • mvn -B clean package -Dmaven.test.skip=true -Dchat2db.finalName=chat2db-community -f chat2db-community-server/pom.xml -pl chat2db-community-start -am - passed; 48 modules succeeded in 37.304s.
• Manual verification: Started an isolated Community Web runtime on frontend 8890 and backend 10826. The frontend compiled successfully in 15.28s; /, direct /api/system, and proxied /api/system returned HTTP 200. The runtime-only Files visibility override used for this local Community Web check is not included in this PR.
• UI evidence: N/A - validated interactively in the isolated local runtime; no screenshot or recording attached.

Risk and compatibility

• Public API or stored data: N/A - frontend workspace state only.
• Database or driver compatibility: N/A - no database or driver changes.
• Network, privacy, or security: N/A - no network or security behavior changes.
• Community / Local / Pro boundary: The workspace navigation logic is shared; the runtime-only Community Web Files visibility override is excluded.
• Backward compatibility: Intentionally removes automatic Files/Data Browser panel switching. Explicit panel clicks continue to locate the active tab in the selected browser.

Reviewer map

• Start here: chat2db-community-client/src/pages/main/workspace/components/WorkspaceLeft/index.tsx, then utils/activeTabTarget.ts and utils/activeTabLocator.ts.
• Failure condition: Activating a Console changes the selected Files/Data Browser panel, or manually selecting a panel fails to locate the active tab there.
• Rollback or disable path: Revert commit b35f1e55.

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: OpenAI Codex assisted with implementation, tests, runtime verification, and PR preparation. The contributor reviewed the resulting scope and behavior.