Optimize script type lookup

[bobmoser76]

Summary:

• maintain a hash index for allocated script type names
• replace repeated linear type searches with hashed lookup
• rebuild or clear the index alongside program restart and teardown
• keep compiler filenames in stable storage while includes update the filename cache

Validation:

• fresh Meson debug build with the native Linux platform backend
• client, dedicated server, and unified game module linked successfully
• git diff --check