debuginfo: Support backward-compatible debug info versions

Explore how `miden-debug` can read older package debug-info versions while `Processor` remains tied to the latest VM/package format. We should clarify whether compatibility belongs in the debugger, package decoding, or a separate versioned adapter layer.

Look at the package decoding logic in the codebase, likely in a module like `src/package.rs` or `src/debug_info.rs`. Examine how debug info is currently read and the versioning scheme. Determine where to add version detection and adaptation logic, then test with older debug info files to ensure backward compatibility.

Written by the indexing model from the issue text.