Add support for `npm-shrinkwrap` & Deno

- Deno: Parse the jsr section into a map keyed by `name@version`, link edges from `jsr[*].dependencies`, resolve `"jsr:@scope/name"` via specifiers, and build root from `workspace.dependencies`. This should be enough for most of the folks, but maybe needs more research.

- shrinkwrap: From what I understand we can reuse current npm parser (assuming we're targeting `lockfileVersion` >= 2/3)

The issue describes adding parsers for npm-shrinkwrap.json and Deno's jsr.json. Start by examining the existing npm parser in the codebase to understand the structure. For Deno, research the jsr specification and workspace dependencies. Implement parsing logic that outputs a consistent map format. Test with sample lockfiles to ensure compatibility.

Written by the indexing model from the issue text.