Handle cc-switch model catalog takeover

[Rat0323]

Summary

• recognize cc-switch-model-catalog.json as a catalog managed by cc-switch rather than a user-authored custom catalog
• let Codex++ take over that stale pointer when applying a relay profile
• preserve unrelated user-defined external model catalogs
• support relative paths, absolute Windows paths, slash differences, and filename case differences

Root cause

cc-switch can leave model_catalog_json = "cc-switch-model-catalog.json" in ~/.codex/config.toml. Codex++ previously treated every catalog outside its own model-catalogs/ directory as user-managed and preserved it. As a result, Codex could continue loading cc-switch's model metadata, so the context-window and capability metadata generated by the active Codex++ profile did not take effect.

Behavior after this change

When Codex++ applies a profile and finds the known cc-switch catalog filename, it removes the stale pointer and either:

• writes the Codex++ managed model-catalogs/<profile>.json pointer when the profile needs catalog metadata; or
• leaves model_catalog_json absent when the profile does not need a catalog.

Other external catalog paths remain untouched.

Validation

• cargo test -p codex-plus-core --test relay_config — 110 passed, 0 failed
• cargo fmt --all
• git diff --check
• clean locked release build of codex-plus-launcher and codex-plus-manager

CI follow-up

The initial Windows artifacts run failed in the repository's existing byte-exact theme asset test because Windows checkout converted uncovered LF assets to CRLF. The hashes in the failure exactly matched the CRLF-transformed bytes; both macOS artifact jobs and all relay configuration tests passed. This branch now also adds the missing eol=lf coverage in .gitattributes without changing any theme asset or expected hash.

Related repository issue: #1732.

Additional validation:

• cargo test -p codex-plus-core --test upstream_theme_assets --test relay_config --locked — 112 passed, 0 failed
• all 18 byte-exact tested assets resolve to text eol=lf