[Alexbeav]

SYSTEM.CNF boot names such as SLUSP012.06 and SLUSP013.46 must produce the same canonical serial in the builder and the runtime's mounted-disc report. Normalize them to SLUS-01206 and SLUS-01346 after a known territory prefix. Reject the unusual-name build when the selected runtime does not declare normalization version2; ordinary names continue to work with older runtimes. Both CHD and extracted-disc admission paths apply the check before generating a roster.

The public producer capability is in RetroPortingToolKit/psxrecomp#868 . This PR changes no supported-version defaults, core selection or release artifact. An older selected reader remains unsuitable for those unusual names and receives an explicit error.

Validation on current main4b4f1d05f9e7634e4b44a52e15b29c92bf34527c, Windows/Python3.14:

• The exact new normalization/capability tests fail before and pass after: both unusual names, case/path handling, ordinary US/PAL/Japanese names, nonserial/unknown/six-letter forms, mounted-report agreement and missing/version1/version2 runtime declarations.
• Full repository unittest discovery:40tests, zero failures, two existing optional-package skips. All inputs are synthetic; no title or disc-swap pass is claimed.
• Source diff/whitespace checked; existing line endings retained. No media, BIOS, saves, binaries or dependency payload changes.

Developed with AI assistance; validated as described (test evidence in PR body). AI writes the code and the PR, but I always test before I send something up. Happy to iterate on this process with your feedback.