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

[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 checking this against the real _x.ai/mcp/servers_updated payload, @maikunari. Glad the array-form env: [{name, value}] path matches what you saw. Appreciate the review.

[jatinder14]

Thanks @maikunari. Updated in ad50de0.

mcpServers[].env values are now always redacted for both object maps and {name, value} arrays, including names like DATABASE_URL. Elsewhere we still only redact secret-shaped keys. Added a test for the blanket MCP env case, and confirmed generic env values outside that path are unchanged.

Agreed on desktop-side logging. That managed-agent path sits outside buzz-acp, so I will leave it as a follow-up.

[Bartok9]

Independent review (Bartok9) — 2026-07-30

Verdict

Solid defensive fix for #2819. Prefer landing this over a parallel stack.

What I checked

• Wire path still talks to the agent unmutated; only acp::wire debug lines + observer payloads are scrubbed — correct boundary.
• Dual shape coverage: secret-shaped keys (apiKey, *_TOKEN, …) and full MCP env under mcpServers (handles Grok-style {name,value} pairs and map envs / DATABASE_URL). Matches the failure mode where agents rebroadcast MCP config.
• Parse-error observe lines also redact the raw line — nice; avoids side channel.
• Unit tests pin the interesting cases (incl. keyboard false positive avoidance).

Non-blockers

• Branch may want a rebase onto latest main before merge (hygiene).
• Optional later: shared helper with desktop’s split_config_key if they ever drift (comment already notes the mirror).

Recommend merge. Thanks @jatinder14 — this is the right layer for the defensive half of #2819.

[jatinder14]

Thanks @Bartok9 for the thorough independent review. Glad the wire/observer boundary and the blanket mcpServers env redaction look right.

I'll rebase onto latest main for hygiene. Agreed that sharing a helper with desktop's split_config_key can be a follow-up if those paths start to drift.