[Pika-Yalei]

Summary

AI text-copy actions fail over non-loopback HTTP because they bypass the shared clipboard fallback. SQL Favorites also replace and bind the entire query instead of inserting reusable SQL snippets.

• Route AI message, reply, and SQL copying through the shared HTTP-compatible text copier, retain session-access checks, and show success only after copying succeeds. Use one Monaco entry point to guard WebKit clipboard setup when the required browser APIs are unavailable.
• Insert favorites at the cursor or replace only the selection, with undo/redo support. Remove favorite-specific dirty state, tab associations, and close/discard prompts while preserving ordinary query drafts.
• Keep one save icon with Save as new favorite and Save to existing favorite. The latter uses version checks and defaults to the current query's most recently inserted favorite; users can change the target. Each query remembers that insertion independently across refreshes.
• Remove AI conversation image sharing, its dedicated rendering dependency, assets, and translations. Move shared toast close buttons inside their containers and remove the circular border.
• Update reusable browser regression procedures. Release notes are unchanged.

Related Issues

Closes #417
Closes #418

Test Plan (Required)

• Not tested (explain why below)
• Unit tests
• Integration tests
• Frontend lint / build
• Backend build
• Manual verification

Details:

• npm run lint -- --no-fix: passed.
• npm run check-i18n: passed with the changes staged; changed component locale references were also checked directly in both languages.
• npm run test:unit -- --runInBand: 2 suites and 8 tests passed.
• cd package && ./all_build.sh web: passed after the final source change. Restarted DmAloneLauncher through IDEA and confirmed startup and /healthcheck readiness.
• Built-in browser checks covered LAN HTTP and localhost text copying, multiline SQL and reply contents, favorite insertion and selection replacement, undo/redo, explicit saving, version conflicts, per-query defaults, tab switching, refresh persistence, and removed sharing entries. No SQL was executed.
• Verified toast close placement, mouse and keyboard dismissal, automatic dismissal, and responsive layouts at 1440x900, 1024x768, and 390x844.
• Isolated checks covered failed insertion, delayed responses, off-page default lookup, deleted favorites, datasource-type mismatches, and clipboard-service capability guards.
• Coverage limits: Safari/WebKit runtime and every read-only/Diff business entry were not exercised in the browser; capability guards and shared import paths were verified separately.

Checklist

• The PR title clearly describes the change.
• The change follows the repository coding standards.
• Documentation was updated when behavior or usage changed.
• Tests were added or updated for behavior changes.
• I confirmed that generated files, dependency directories, logs, and local build artifacts are not included.