Add Scripts tab

[bburda]

Summary

Add a Scripts tab to the entity resource panel with script listing, upload, execution with arguments, and execution status tracking.

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Proposed solution (optional)

• New ScriptsTab component
• List scripts via GET /{entity_type}/{entity_id}/scripts
• View script details via GET /{entity_type}/{entity_id}/scripts/{script_id}
• Upload new script via POST /{entity_type}/{entity_id}/scripts (when allow_uploads is enabled)
• Execute script with arguments via POST /{entity_type}/{entity_id}/scripts/{script_id}/executions
• Track execution status via GET /{entity_type}/{entity_id}/scripts/{script_id}/executions/{execution_id}
• Cancel/stop execution support

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Additional context (optional)

Depends on sovd_web_ui#42 (client migration). Gateway supports script execution with ScriptProvider plugin interface since v0.4.0. Upload capability is controlled by allow_uploads config toggle.