Fix Kass Basher asset loading

[astrovm]

What changed

• replace Kass Basher's broken loader and dependency SWFs with the current Flashpoint archive files
• route the game's Neopets dependency hosts through the existing shared URL-spoof implementation
• support both string URLs and Request objects in that interceptor
• add regression coverage for the required hosts and request forms

Root cause

The bundled 3.2 KB launcher referenced dead remote Neopets assets. The replacement game still loads three archived dependencies, and Ruffle can issue those requests as string URLs, which the existing interceptor did not rewrite.

Impact

Kass Basher now reaches its labeled menu and starts a playable round without relying on the dead upstream URLs.

Validation

• browser-tested the menu and started a round in Ruffle
• bun run quality
• bun run test (120 passing)