Trim unused features from the Hazelwood RAK4631 repeater build

Drop display, GPS, INA, RS232, KISS host and every sensor driver except
SHTC3 (RAK1901) from RAK_4631_repeater_unified_lora_ota, keeping the env
name and therefore OTA target id 05F5FFAE. The Full image shrinks by about
125 KB, leaving more in-place room for LoRa OTA deltas.

check_firmware_capabilities.py accepts capabilities listed in
MESHCORE_LOCAL_OMIT_CAPABILITIES as deliberately omitted, and fails if a
listed one is still present.

local_build.sh

@@ -37,6 +37,23 @@ case "${2:-}" in
   *companion*) LOCAL_BUILD_FLAGS="${LOCAL_BUILD_FLAGS} -DBLE_PIN_CODE=123456" ;;
 esac
 
+# Hazelwood RAK4631 repeaters (KM-Test, Treebeard): no display, GPS, INA, RS232
+# or KISS host; Treebeard's only sensor is a RAK1901 (SHTC3). Dropping the rest
+# shrinks the image by ~100 KB, which leaves more in-place room for LoRa OTA
+# deltas. The env name must stay as is: it is the OTA target id (05F5FFAE).
+# Upstream qualification still expects these features from the env name, so
+# list them for scripts/check_firmware_capabilities.py to accept as omitted.
+case "${2:-}" in
+  RAK_4631_repeater_unified_lora_ota)
+    LOCAL_BUILD_FLAGS="${LOCAL_BUILD_FLAGS} -UDISPLAY_CLASS -UENV_INCLUDE_GPS -UWITH_RS232_BRIDGE -UMESH_ENABLE_HOST_KISS"
+    for sensor in AHTX0 BME280 BME680 BME680_BSEC BMP085 BMP280 INA219 INA226 INA260 INA3221 LPS22HB MLX90614 RAK12035 SHT4X VL53L0X; do
+      LOCAL_BUILD_FLAGS="${LOCAL_BUILD_FLAGS} -UENV_INCLUDE_${sensor}"
+    done
+    MESHCORE_LOCAL_OMIT_CAPABILITIES="bridge.rs232,bridge.rs232.merged,sensor.gps,sensor.ina219,sensor.ina226,sensor.ina260,sensor.ina3221,radio2.kiss.host,radio2.kiss.usb"
+    export MESHCORE_LOCAL_OMIT_CAPABILITIES
+    ;;
+esac
+
 export PLATFORMIO_BUILD_FLAGS="${PLATFORMIO_BUILD_FLAGS:+${PLATFORMIO_BUILD_FLAGS} }${LOCAL_BUILD_FLAGS}"
 
 if [ -d /opt/homebrew/bin ]; then

scripts/check_firmware_capabilities.py

@@ -301,6 +301,25 @@ def main() -> int:
             }
         )
 
+    # Local builds may deliberately compile features out of an existing OTA
+    # identity. Listed capabilities must then be absent: drop their checks and
+    # record the omission as a reduction. One that is still present means the
+    # trim did not apply, so it fails.
+    omitted = {value.strip() for value in
+               os.environ.get("MESHCORE_LOCAL_OMIT_CAPABILITIES", "").split(",") if value.strip()}
+    kept_checks = []
+    for check in checks:
+        if check["capability"] not in omitted:
+            kept_checks.append(check)
+        elif check["present"]:
+            print(f"capability check failed: {check['capability']} is listed in "
+                  "MESHCORE_LOCAL_OMIT_CAPABILITIES but still present", file=sys.stderr)
+            malformed = True
+        else:
+            args.reduction.append(f"locally omitted: {check['capability']}")
+    checks = kept_checks
+    args.capability = [value for value in args.capability if value not in omitted]
+
     capabilities = stable_unique(
         args.capability + [check["capability"] for check in checks]
     )