* fix(security): redact secrets in background process + foreground env-dump output
Terminal-output redaction was incomplete (#43025):
- Gap 1: process(action=poll/log/wait) returned background stdout verbatim —
no redaction at all. A background printenv/server/test emitting a key leaked
raw to the model, session.db, and CLI display. Same for the gateway
background-process watcher's completion/progress notifications.
- Gap 2: the foreground terminal path hardcoded code_file=True, which skips the
ENV-assignment pass, so an opaque token (no vendor prefix) from env/printenv
leaked even there.
Adds agent.redact.redact_terminal_output(output, command) as the single policy
for ALL terminal-output surfaces: env-dump commands (env/printenv/set/export/
declare) get the ENV-assignment pass (code_file=False) to mask opaque tokens;
other commands stay on code_file=True to avoid false positives on source dumps.
Wired into terminal_tool, process_registry (_handle_process boundary), and the
gateway watcher. Respects security.redact_secrets (no force) — opt-out preserved.
* docs: add infographic for #43025 terminal-output redaction fix