fix(cli): safely patch Codex TOML stdio args

[fahreddinozcan]

Summary

• replace the line-by-line TOML/JSON parsing path with a focused, dependency-free TOML string-array editor
• patch only the existing Context7 args value so pinned package versions, comments, cwd, inline env, and nested environment tables remain untouched
• support multiline arrays, trailing commas, comments, literal/basic strings, escapes, and CRLF
• fail closed without writing when an existing stdio entry cannot be edited safely
• keep the TOML parsing/editing utilities isolated in setup/toml-editor.ts

Fixes #3060

Verification

• pnpm --filter ctx7 test — 258/258 passed
• pnpm --filter ctx7 typecheck
• pnpm --filter ctx7 lint:check
• pnpm --filter ctx7 format:check
• pnpm --filter ctx7 build
• git diff --check

[linear-code]

CTX7-2471

[context7]

Docs7 preview for context7.com

Status	Commit	Updated (UTC)
✅ Ready (visit preview)	e028827	2026-08-25 08:07