High entropy string detection

[kunickiaj]

Try to automatically redact secrets if user forgets or accidentally shares.

[kunickiaj]

Current triage: still relevant.

We already do some sanitization/redaction in the current codebase:

• strip <private>...</private> blocks
• redact some known auth/token shapes

But there is not a general high-entropy secret detector in the shipped TS path, so this remains a valid follow-up if we want broader defense-in-depth for accidental secret capture.