feat(host): log virtual DualSense pad creation (match the X-Box path)

The uinput X-Box 360 backend logs "virtual gamepad created" on success, but
the UHID DualSense backend logged only on failure — so a working DualSense
session was silent and indistinguishable in the logs from one where no pad
was ever created. Add the matching success log.

This makes a DualSense-not-working report self-diagnosing: the host now logs
either "virtual DualSense created (UHID hid-playstation)" or the existing
"virtual DualSense creation failed — controller input disabled" (which fires
when /dev/uhid isn't writable — i.e. the 60-punktfunk.rules uhid rule isn't
installed or the user isn't in the 'input' group).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/punktfunk-host/src/inject/dualsense.rs

@@ -607,6 +607,7 @@ impl DualSenseManager {
         }
         match DualSensePad::open(idx as u8) {
             Ok(p) => {
+                tracing::info!(index = idx, "virtual DualSense created (UHID hid-playstation)");
                 self.pads[idx] = Some(p);
                 self.state[idx] = DsState::neutral();
                 self.last_rumble[idx] = (0, 0);