feat(cortecs): add deepseek-v4-flash-0731

[murdurn]

Adds deepseek-v4-flash-0731 to the cortecs provider.

Mirrors the override-only structure already used for deepseek-v4-flash in
providers/cortecs/models/deepseek-v4-flash.toml

[github-actions]

Action items

• [medium] [violation] providers/cortecs/models/deepseek-v4-flash-0731.toml:8 - Check: Currency conversion / source notes must be a leading top-of-file comment block above the first key. Why: The EUR→USD note sits mid-file after interleaved; AGENTS requires rate/date conversion notes in the leading header (sync and repo convention drop non-leading comments). Action: Move the conversion comment (ideally with original EUR unit prices and a Cortecs pricing/API citation) to a leading block above base_model.
• [low] [possible mistake] providers/cortecs/models/deepseek-v4-flash-0731.toml:10 - Check: Material cost changes should cite direct provider pricing evidence. Why: New USD costs (input/output/cache_read) differ sharply from the existing Cortecs deepseek-v4-flash entry and cannot be reviewed from the PR body alone. Action: Add a PR-body (or leading TOML) citation to Cortecs pricing/docs stating the EUR list prices and what each cost field maps to.

[rekram1-node]

/oc fix this:
[medium] [violation] providers/cortecs/models/deepseek-v4-flash-0731.toml:8 - Check: Currency conversion / source notes must be a leading top-of-file comment block above the first key. Why: The EUR→USD note sits mid-file after interleaved; AGENTS requires rate/date conversion notes in the leading header (sync and repo convention drop non-leading comments). Action: Move the conversion comment (ideally with original EUR unit prices and a Cortecs pricing/API citation) to a leading block above base_model.

[opencode-agent]

Moved the EUR→USD conversion note (with EUR list prices and Cortecs API citation) to a leading header above base_model.

opencode session  |  github run

[github-actions]

No actionable findings.