tune: retune vision and gimbal angle PID, fix manual mode velocity hold

- Vision PID: increase Kp to 100, zero Ki/Kd, tighten CoefA/B
- Gimbal angle PID: reduce to P-only (Kp=1), lower IntegralLimit,
  remove derivative/output filters, unify MaxOut to 2000
- Manual mode: hold last velocity command on lost frames instead of
  stopping
- Debug mode: reset debug_updated flag on mode switch
- Remove stale .vscode settings copy

.vscode/settings copy.json

@@ -1,11 +0,0 @@
-{
-    "files.associations": {
-        "stm32f4xx_hal_def.h": "c",
-        "bsp_usb.h": "c",
-        "usb_device.h": "c",
-        "usbd_cdc.h": "c",
-        "usbd_conf.h": "c",
-        "usbd_desc.h": "c",
-        "usbd_cdc_if.h": "c"
-    }
-}