Let the probe's clock be its proof, not disable_cpu_ep_fallback

The strict flag refused the Hexagon over the ten quantise/dequantise
nodes at the graph's edges that QNN declines by policy, which cost
microseconds. A provider that hands real work to the CPU is slower than
the CPU floor and the timing already rejects it; the tablet measured
2.3 ms on the NPU against a 29.7 ms floor.

core/dr-inference-engine/src/engines.rs

@@ -89,7 +89,7 @@ pub fn run() {
         }
         log::info!("inference: compiling {name} for {}", rung.label());
         let started = std::time::Instant::now();
-        match crate::session::build(rung, role, &bytes, &cfg, false) {
+        match crate::session::build(rung, role, &bytes, &cfg) {
             Ok(session) => {
                 drop(session);
                 let mut s = state().lock().unwrap();