fix(acp): redact secret-shaped env values from wire logs and observer feeds

[jatinder14]

Summary

• Redact secret-shaped keys (*_API_KEY, *_TOKEN, *_SECRET, camelCase apiKey, ACP {name,value} env pairs, …) before acp::wire debug logs and observer acp_read/acp_write emit.
• Agent stdin/stdout is unchanged; only logging/observer copies are scrubbed.
• Adds unit tests covering map env, ACP env arrays, and wire-line redaction.

Fixes #2819

Test plan

• cargo test -p buzz-acp --lib redact::
• Spot-check: with RUST_LOG=acp::wire=debug, trigger an agent notification containing MCP env and confirm keys land as [REDACTED] in logs/Raw Event rail

Made with Cursor

[maikunari]

Reporter here — thanks for the fast pickup. Reviewed against the actual payload I observed: the array-form env: [{name, value}] handling matches what grok emits in _x.ai/mcp/servers_updated, and the sink coverage (observer + both wire directions + parse-error paths) looks complete for this crate. Two points:

1. Suggest redacting all values inside mcpServers[].env, unconditionally — the secret-shaped heuristic misses credentials in non-secret-named variables (DATABASE_URL=postgres://user:password@host, AUTH_HEADER, etc.). Env values are agent config, never display data, so there's no cost to blanket redaction within that path; keep the heuristic for generic JSON elsewhere.
2. The original report also mentioned desktop-side logging — if the managed-agent runtime logs raw notifications anywhere in desktop/src-tauri, that path isn't covered by this PR (fine as a follow-up, just noting scope).

With point 1 addressed I'd consider this a complete fix for the buzz-acp half. 🐝

[jatinder14]

Thanks for the review and for confirming the array-form env: [{name, value}] path against the real _x.ai/mcp/servers_updated payload — that was the exact case this was written for. Appreciate you taking a look @maikunari.