Autopilot approval policy

Change a channel's autopilot approval policy (the rule that decides whether an agent draft for a plan slot is scheduled automatically or waits for a human). autopilotPolicy: manual (every draft waits for approval), streak (automatic once the channel has config.streakTarget consecutive approved agent posts), auto (automatic right away). config is a partial object merged onto the stored config; pass null to reset it to defaults. Keys: streakTarget (3–20), autoPostTypes (subset of common | news), quietHours ({ from: "HH:mm", to: "HH:mm" } in the plan's time zone, or null), dailyAutoLimit (1–50 or null = no limit). Guardrails (recommendation review/revise, banlist hits, paused generation) always send a draft to approval regardless of the mode. Requires the team owner or a role allowed to manage agent jobs; returns the effective policy and changed=false when nothing differed.