Resolve each caller-selected Electron path once at the application boundary, collect field-specific failures with original causes, and pass canonical paths directly to the provider. Update direct provider consumers and route the real verifier through the shared application workflow.
Validation: public CLI/MCP invalid-path acceptance, canonicalization boundary, provider tests, and cancellation/cleanup checks. Live Electron launch was not verified. This does not address the separate Playwright launch-rejection crash in #2269.
Fixes#2272