test: close web platform command-coverage gaps from #1426 #1900

Part of #1426.

The web platform manifest records these commands as known gaps because HEAD has no command-specific web evidence that meets the manifest contract, even where generic runtime facts or handlers exist:

• artifacts
• boot
• shutdown
• logs
• events
• replay
• test
• install
• reinstall
• push
• batch
• diff
• trace
• press
• install-from-source

Follow-up work should add or identify executable web command evidence before changing the manifest rows. Keep the existing live web smoke scope unchanged unless a separate platform-evidence decision explicitly expands it.