Infer per-package source roots from classgraph-view --input

Infer per-package source roots from classgraph-view --input

Add a --source-root PKG=PATH override and infer a default per-package
root from each --input dir's parent. Schema gains iiDefinedIn /
fiDefinedIn (filled in at merge time from the dump's mdPackage), so
orphan instances resolve under the *defining* package, not the
class's. Render embeds the resulting map; viewer's editor links look
up the per-package root before falling back to the localStorage
override.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>