encoding-safety

name	encoding-safety
description	Prevent encoding/mojibake regressions when Codex creates or edits Markdown notes, AGENTS.md/CLAUDE.md instructions, or interactive HTML/iframe tools in this Obsidian vault, especially when Chinese text, CJK UI labels, LaTeX, or Windows PowerShell file writes are involved.

Encoding Safety

Use this skill whenever editing or generating Markdown, HTML, JavaScript, or project instructions that may contain non-ASCII text in this vault.

Non-negotiable rule

Never embed Chinese/CJK text directly inside a PowerShell here-string or shell command payload. The command transport may turn it into question marks before Python or the editor sees it.

Safe write patterns

Prefer one of these patterns:

1. ASCII-only generated artifacts when acceptable, especially for HTML UI labels.
2. Python file writes with Unicode escapes such as "\\u53cc\\u91cd", then write with encoding="utf-8".
3. Base64-encoded UTF-8 payloads decoded inside Python before writing.
4. Read existing UTF-8 text from a file and transform it, instead of retyping non-ASCII text in the shell command.
5. For small Markdown patches, use apply_patch only when the patch text is known to survive intact; otherwise use Unicode escapes/base64.

Required validation after writing

After any write that could affect CJK text:

• Re-read the changed file with encoding="utf-8".
• Check the exact edited region, not just file existence.
• Search for mojibake markers: three consecutive question marks, replacement character U+FFFD, and unexpected long runs of ?.
• For HTML/JS, run node --check on extracted scripts when JavaScript is present.
• Confirm <meta charset="utf-8"> exists in standalone HTML tools.

Minimal validation logic: read the file as UTF-8, print the edited slice, then test whether three consecutive question marks or U+FFFD appears.

Obsidian HTML iframe tools

For tools/*.html embedded in notes:

• Include <meta charset="utf-8">.
• Use absolute file:///C:/Personal%20Profile/Profile/MathPhysCore/tools/...html iframe paths in notes.
• If CJK UI text is not essential, prefer English/ASCII UI labels to eliminate encoding risk.
• If CJK UI text is essential, generate the file via Unicode escapes or base64 and validate rendered text by re-reading the file.

If mojibake is found

1. Stop editing the affected region further.
2. Reconstruct the intended text from context or user selection.
3. Rewrite using a safe write pattern above.
4. Validate before responding to the user.