Fix AGL velocity estimation using squared acceleration weight factor

The AGL velocity update was incorrectly using squared acceleration
weight factor (sq(accWeightFactor)) while the altitude update uses
linear weight. This creates physical inconsistency where position
and velocity respond differently to the same acceleration.

With accWeightFactor=0.5 (moderate confidence):
- Altitude receives 50% of acceleration (correct)
- Velocity was receiving 25% of acceleration (wrong - squared)

This fix removes sq() from the velocity update to match the altitude
update, making both integrations physically consistent with standard
kinematic equations.

May fix #10314
May be related to #10567

Author: sensei-hacker

src/main/navigation/navigation_pos_estimator_agl.c

@@ -149,7 +149,7 @@ void estimationCalculateAGL(estimationContext_t * ctx)
         // Update estimate
         posEstimator.est.aglAlt += posEstimator.est.aglVel * ctx->dt;
         posEstimator.est.aglAlt += posEstimator.imu.accelNEU.z * sq(ctx->dt) / 2.0f * posEstimator.imu.accWeightFactor;
-        posEstimator.est.aglVel += posEstimator.imu.accelNEU.z * ctx->dt * sq(posEstimator.imu.accWeightFactor);
+        posEstimator.est.aglVel += posEstimator.imu.accelNEU.z * ctx->dt * posEstimator.imu.accWeightFactor;
 
         // Apply correction
         if (posEstimator.est.aglQual == SURFACE_QUAL_HIGH) {