feat(studio): add new-query shortcut and keyboard guide

[2160039878-cyber]

Description

Open a query tab with Ctrl+Alt+Shift+N / Command+Option+Shift+N using the existing new-tab action. The new-tab button exposes the binding in its tooltip and accessibility metadata. A shared keyboard guide opens with ? outside text fields, from the command palette, or from the Data Profiler's keyboard button.

Closes #745. Closes #746.

Type of Change

• New feature
• Documentation and regression tests

Changes Made

• Preserve reserved browser bindings, composition, repeated keys and AltGr character input. Embedded new-tab handling is scoped to the workspace receiving the event.
• List application and registered query-editor bindings with their scope, including the editor's F1 command palette. Reuse the existing dialog, restore focus on close, and close the guide before an underlying profiler on Escape.
• Wire the guide into both Studio and StudioWorkspace. Isolate its real Radix dialog tests with DataProfiler in the existing component runner to avoid unrelated module mocks.

Testing

• TDD: new shortcut regressions failed before implementation; the guide's component/wiring regressions failed before implementation.
• Project-isolated component run targeting StudioTabBar|KeyboardShortcutsDialog|CommandPalette|DataProfiler|^Studio >|StudioWorkspace: 147 passed. After the final AltGr compatibility adjustment, reran StudioTabBar: 33 passed.
• Component-runner coverage guard: 3 passed.
• Passed locally: format, lint, typecheck, knip, readme:check, chart:check, channels:showcase:check, security:check, build, build:lib, attw. Builds used clean commit d5187606aa2c5f63f225163015ba5536c5f931f9.
• Browser smoke check used the actual components and production CSS in an isolated local fixture: new-tab shortcut, ? guide, guide focus restoration, command-palette entry, and embedded input scoping passed. A host input did not create an embedded tab; the embedded query input did. This was not a full application E2E test or a native macOS keyboard test.
• Full local bun run test, coverage and app E2E were not run: this Windows host lacks Helm/chart dependencies and working Docker; existing SQLite cleanup also encounters Windows file locks. CI must verify the full suite and 100% line coverage.

Environment: Windows, Node.js 24.18.1, Bun 1.4.2.

Checklist

• Claimed both issues before implementation, reviewed the final diff and updated documentation.
• Added regression tests and passed relevant local checks.
• Required CI test job passes the 100% line-coverage gate.

Additional Notes

AI-assisted implementation and validation using Codex. No dependencies, storage migrations or provider changes. Browser extensions, OS shortcuts and keyboard layouts can override application key combinations.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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