fix(approval): redact secrets in user-facing approval prompts

The dangerous-command approval prompt renders the flagged command so the
user can decide whether to approve. If the agent constructed it with a
credential (curl -H 'Authorization: Bearer sk-...', psql postgres://user:pw@host,
an execute_code script with api_key = 'sk-...'), that secret hit stdout and,
via the gateway notify payload, Discord/Slack messages — which are
screenshottable and forwardable.

Apply the existing agent.redact.redact_sensitive_text() to every user-facing
approval surface. Redaction is display-only: the raw command still executes
after approval, and approval persistence keys off pattern_key (not the command
text), so the allowlist is unaffected. Decision context (URL, flags, command
structure) is preserved; only the secret value masks.

Covers all surfaces, including the execute_code path the original PR missed:
- prompt_dangerous_approval(): callback + stdout fallback
- check_all_command_guards(): gateway approval_data + cron/batch pending fallback
- check_execute_code_guard(): gateway approval_data + no-notifier pending fallback
  (script body can embed credentials)

Adds TestApprovalPromptRedaction covering callback redaction, no-over-redaction
of clean commands, and the execute_code pending fallback.

Salvaged from PR #13139 by @sgabel; extended to the execute_code surface.

scripts/release.py

@@ -45,6 +45,7 @@ ACP_REGISTRY_MANIFEST = REPO_ROOT / "acp_registry" / "agent.json"
 
 # Auto-extracted from noreply emails + manual overrides
 AUTHOR_MAP = {
+    "5823452+sgabel@users.noreply.github.com": "sgabel",  # PR #13139 salvage (redact secrets in user-facing approval prompts)
     "cyb3rwr3n@users.noreply.github.com": "cyb3rwr3n",  # PR #11333 salvage (sanitize FTS5 queries for natural-language recall in holographic memory)
     "9350182+codexGW@users.noreply.github.com": "codexGW",  # PR #12302 salvage (Discord raw <@!ID> mention detection + drop bare mention-only pings)
     "186512915+lEWFkRAD@users.noreply.github.com": "lEWFkRAD",  # PR #53848 salvage (stream the MoA aggregator response to the user)