Index Runtime Replacement

The Index runtime replacement exposes an executable app entrypoint at

apps/index/release/bin/index. It dispatches the accepted command corpus through

0x0-owned pure source surfaces and the local runtime contracts.

The release metadata under apps/index/release/ records the package source,

vendored lockfile, artifact hashes, and rollback anchor. The normal path must

not invoke a jmp0x1b runner.