refactor(ui): migrate views to Querya UI Kit and add architectural guard tests (#1039)

[ZhuchkaTriplesix]

Summary

Migrates all legacy raw Material components (AlertDialog and CircularProgressIndicator) and custom search inputs across lib/ to Querya UI Kit design system components (QueryaModalDialog, QueryaConfirmDialog, QueryaSpinner, QueryaSearchField). Also introduces CI architectural guard tests to prevent regression.

Closes #1039

Key Changes

1. Dialogs Migration:
   • Replaced raw Material AlertDialog occurrences across database view modules (SQLite, PostgreSQL, MySQL, Redis, Extensions, Settings/Themes) with QueryaModalDialog and QueryaConfirmDialog.
   • Updated QueryaModalDialog actions to use Wrap to ensure action buttons never cause RenderFlex overflow on narrow dialog layouts.
2. Progress Indicators Migration:
   • Replaced ~54 raw material.CircularProgressIndicator occurrences across lib/ with QueryaSpinner (using appropriate size tokens: .sm, .md, .lg and optional labels/colors).
   • Only lib/shared/widgets/querya_spinner.dart remains as the design-system provider of the underlying progress widget.
3. Search Fields Migration:
   • Replaced custom search inputs in RedisKeysView, MongoDocumentsView, and ResultsTab with QueryaSearchField.
4. Architectural Guard Tests:
   • Added test/guards/no_raw_material_dialogs_test.dart to assert zero raw AlertDialog usages across lib/.
   • Added test/guards/no_raw_progress_indicators_test.dart to assert zero raw CircularProgressIndicator usages across lib/ (exempting querya_spinner.dart).
   • Verified with existing no_material_dropdowns_test.dart.

Verification

• flutter analyze: 0 issues found (clean).
• flutter test test/guards/: 3/3 guard suites passed.
• flutter test: 1,954+ unit & widget tests passed.