Use package:// URIs for stable, machine-independent file references

[akhilles]

Note

Medium Risk
Touches core path resolution and layout sync plumbing across Rust and Python; incorrect URI/root mapping could break file discovery or produce wrong artifact paths across workspaces/dependencies.

Overview
Build artifacts (netlists/layout sync inputs) now prefer stable, machine-independent package://… URIs instead of absolute/relative filesystem paths.

This adds package-root tracking to the schematic JSON (package_roots) and introduces package:// parsing/formatting + resolution in pcb-sch/pcb-zen-core, updating File()/Path(), footprint path handling, and layout-path handling to emit/consume these URIs.

Layout generation/sync is updated to resolve layout_path, footprint library paths, and fragment paths via package roots (including Python lens adapter updates), and tests/resources/snapshots are refreshed accordingly (new pcb.toml workspaces, Layout(...) usage, and asset-based footprint references).

^{Written by Cursor Bugbot for commit 1c1f283. This will update automatically on new commits. Configure here.}

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{Bugbot Autofix is OFF. To automatically fix reported issues with Cloud Agents, enable Autofix in the Cursor dashboard.}