UI: platform profile picker for validation / batch workflows

[fernandotonon]

Problem

CLI-first workflows are insufficient for artists using QtMeshEditor: they need to pick a target profile when validating assets from the GUI (batch scan, pre-export check, or future integrated linter panel).

Proposed solution

• Add UI surface (QML preferred per project guidelines) to choose Platform profile for operations that invoke or mirror ScanEngine / batch validation—exact placement follows existing patterns (e.g. Batch Exporter, Welcome, or Inspect panel).
• Persist last-used profile in QSettings.
• Optional: display profile description tooltip from JSON description.

Scope

• GUI wiring only; reuse CLI merge logic internally (shared C++ API).

Acceptance criteria

• User can select a profile and run validation consistent with qtmesh scan --target <id> for the same asset set (or document subset).
• Sentry breadcrumb on profile use (ui.action).

Files / components likely affected

• qml/*.qml (new combo box or settings section)
• src/PropertiesPanelController.cpp or dedicated controller
• src/BatchExporter.cpp / related if validation hooks there
• src/mainwindow.cpp if menu entry required

Test strategy

• Qt Test / headless where feasible; manual test checklist acceptable for pure UI if CI limits apply.

Labels

enhancement

Milestone

Milestone 5: UI integration

Dependencies

• Platform profile: JSON schema, loader, and ScanConfig application API #362 and CLI: qtmesh scan --target <profileId> with documented config merge order #363 stable (loader + --target merge API).