fix(cli): add missing min_frames field to CalibrateArgs test helper

E0063 in calibrate.rs:448 — CalibrateArgs gained min_frames in ADR-135
but the default_args() test helper was not updated. min_frames=0 means
'use tier default', matching the existing runtime behaviour.

Co-Authored-By: claude-flow <ruv@ruv.net>

v2/crates/wifi-densepose-cli/src/calibrate.rs

@@ -453,6 +453,7 @@ mod tests {
             tier: "ht20".into(),
             banner_every: 20,
             abort_z_threshold: 2.0,
+            min_frames: 0,
         }
     }
 }