fix(drc): preserve violations in nested report categories

[jinchuntan]

The converter only visited the top level of a KLayout report database. Violations stored in child categories were left out of the JSON output.

It now walks the full category tree and uses KLayout category paths to keep rule names distinct. This also separates a literal dotted name from a nested category with the same text.

Added three regressions for repeated leaf names and deeper nesting and dotted name collisions. All 10 converter tests pass. Black passes for both changed files.

A saved and reloaded report created with KLayout 0.30.12 contains three violations. The original converter exports one and the fix exports all three with their shapes and comments.

The broader utility checks cover 94 cases with 92 passing and one skipped because Yosys is unavailable. The process visibility test fails in this workspace as it also does on unchanged master at 7bcaf47.

A full layout DRC run was not performed.

Prepared with Codex assistance.

[gemini-code-assist]

Code Review

This pull request updates the KLayout DRC conversion utility to recursively traverse nested categories and use the category path instead of its name as the key in the output dictionary. This prevents categories with identical names in different paths from overwriting each other. Unit tests have been added and updated to verify the nested category traversal and path-based keying. There are no review comments to address.

[openroad-ci]

🔍 QoR check

Metrics reflect the PR merge build — i.e. what will land on the target branch.

Commit 8cf3706 · Jenkins build #1 · Baseline: build · View build on dashboard

62 design(s) checked — 0 with regression(s), 0 without a comparable baseline.