gate apple gpu collectors + revert readme change

agent/gpu.go

@@ -708,13 +708,10 @@ func (gm *GPUManager) resolveLegacyCollectorPriority(caps gpuCapabilities) []col
 		priorities = append(priorities, collectorSourceIntelGpuTop)
 	}
 
-	// Prefer macmon on macOS (no sudo). Fall back to powermetrics if present.
-	if caps.hasMacmon {
-		priorities = append(priorities, collectorSourceMacmon)
-	} else if caps.hasPowermetrics {
-		priorities = append(priorities, collectorSourcePowermetrics)
-	}
-	// Keep nvtop as a legacy last resort only when no vendor collector exists.
+	// Apple collectors are currently opt-in only.
+	// Enable them with GPU_COLLECTOR=macmon or GPU_COLLECTOR=powermetrics.
+
+	// Keep nvtop as a last resort only when no vendor collector exists.
 	if len(priorities) == 0 && caps.hasNvtop {
 		priorities = append(priorities, collectorSourceNVTop)
 	}

readme.md

@@ -48,7 +48,7 @@ The [quick start guide](https://beszel.dev/guide/getting-started) and other docu
 - **Network usage** - Host system and containers.
 - **Load average** - Host system.
 - **Temperature** - Host system sensors.
-- **GPU usage / power draw** - Nvidia, AMD, Intel, and Apple (macOS via macmon or powermetrics).
+- **GPU usage / power draw** - Nvidia, AMD, and Intel.
 - **Battery** - Host system battery charge.
 - **Containers** - Status and metrics of all running Docker / Podman containers.
 - **S.M.A.R.T.** - Host system disk health (includes eMMC wear/EOL via Linux sysfs when available).