chore(watchdog): 补 build_watchdog.sh(交叉+宿主测试), 对齐各组件 build_xxx.sh 惯例; 固件打包唯一入口仍是 scripts/build/build_fw_apps.sh

patch_v2/meow_watchdog/build_watchdog.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+# build_watchdog.sh — meow_watchdog 交叉编译（mipsel 静态）+ 宿主测试构建。
+#
+# 用法：
+#   ./build_watchdog.sh          # 交叉编译 → meow_watchdog（mipsel 静态，fw_content.conf 的 /usr/bin/meow_watchdog）
+#   ./build_watchdog.sh host     # 宿主编译 test_wd_fw 并跑宿主回归
+set -e
+cd "$(dirname "$0")"
+ROOT=../../..
+CC="$ROOT/.tools/zig-mipsel-cc"
+
+if [ "$1" = "host" ]; then
+    gcc -Wall -Wextra -Os -DWd_NO_MAIN -Wno-unused-function -Wno-unused-parameter \
+        test_wd_fw.c -o test_wd_fw -lm
+    ./test_wd_fw
+    exit $?
+fi
+
+echo "== meow_watchdog (mipsel static) =="
+"$CC" -Os -Wall -Wextra -static meow_watchdog.c -o meow_watchdog
+ls -la meow_watchdog
+md5sum meow_watchdog
+file meow_watchdog