Expose authoritative portable code sets

[fruwe]

Summary

• define category-specific string enums used by production emitters and derive the deeply immutable PORTABLE_CODE_SETS export from them
• cover all 10 Python-applicable registry categories and 87 category/code entries, excluding implementation-only execution_store_failure and harness-only structural_validation
• compare exact per-category missing and extra codes against generated conformance registry vectors without source scraping or a duplicate expected list
• compare complete logical-scope checkpoint/root and outbox-record maps, including exact key sets, with sabotage coverage for omitted and unexpected records
• preserve public strings, runtime behavior, idiomatic Python names, and package version

The conformance pin advances to merged registry head 5ba78c7. This is the repository-standard minimal pin update needed for the generated closed-code registry vectors; it also contains six merged logical execution-store scope vectors now exercised by the driver.

Validation

• make check (274 passed, 5 skipped)
• focused registry parity, checkpoint profile, and scope sabotage tests (95 passed)
• make conformance against conformance 5ba78c7 and specification cc4b0d7 (288 passed)
• package artifact and public export tests (35 passed)
• distribution build and scripts/verify_distribution.py
• direct wheel import verified PORTABLE_CODE_SETS and the category enum exports

Fixes #78