docs: prefer English for GitHub collaboration

[mirror29]

Summary

• Make English the default language for commit messages, branch names, pull requests, issues, discussions, reviews, release notes, and security reports.
• Update the pull request and issue templates to surface the English-first convention while preserving accessibility exceptions.
• Make the automated DeepSeek pull request review and all non-blocking failure messages use English.
• Add regression coverage for the primary prompt, retry prompt, and every changed failure-output path.

Test Coverage

All 8 changed language-output paths are covered by regression tests.

• Tests: 8 → 12 in tests/test_deepseek_review.py (+4)
• No new application control-flow branches were introduced.

Pre-Landing Review

No issues found. Testing, maintainability, and adversarial reviews completed.

Design Review

No product frontend files changed; design review was not applicable.

Eval Results

No project eval suite maps to this standalone review-script prompt. Prompt contracts are covered by deterministic unit assertions.

Scope Drift

Scope Check: CLEAN. The diff only changes collaboration-language policy, contributor templates, automated PR-review copy, and its tests.

Plan Completion

No plan file detected.

Verification Results

• python3 -m unittest tests/test_deepseek_review.py — 12 passed
• python3 -m py_compile scripts/deepseek_review.py
• bash scripts/check-consistency.sh — 19 passed, 0 failed
• git diff --check
• Orchestration typecheck and Vitest — 535 passed
• Evolver pytest — 113 passed
• Ruff checks for all Python services

The local paper pytest suite could not start because the shared development database references migration 0044, which is not present on main; this is unrelated to the changed files and CI uses a clean migration state.

Test plan

• Confirm all collaboration policy sources prefer English.
• Confirm PR and issue templates request English by default.
• Confirm automated review success, retry, and failure output is English.
• Confirm no temporary dependency links or unrelated branch commits are included.

[github-actions]

Review base: 8d954c2

🤖 DeepSeek V4 Pro PR Review

LGTM.