refactor(toolchain)!: 工具链 plugindev 更名为 hmapdev，module path 改回 gitcode

- 目录 tools/plugindev → tools/hmapdev，可执行文件名/平台产物名同步
  （hmapdev_linux_amd64 等；包格式仍叫 .hmap）
- module path github.com/JianFeeeee/homeagent-sdk/tools/... → gitcode.com/...
  （与仓库实际托管一致；核心仓不依赖该 path，改动无外部影响）
- SDK 存储目录 ~/.homeagent/plugindev/sdk → ~/.homeagent/hmapdev/sdk
  新目录不存在而旧目录存在时沿用旧目录 → 已装 SDK 版本不会丢失
- 命令表/usage/--help/生成项目 README/示例 README/NSIS 安装器/
  package/build.sh/build-examples.sh 全部同步；PLUGINDEV 环境变量保留兼容
- sdk/ 目录零改动（公开接口不变）

验证：
- go build ./... ok；go test ./tools/hmapdev/ ok（含模板接线守卫 TestProcTemplate_CoversAllCoreMethods）
- bash -n package/{build,build-examples}.sh ok
- 端到端：hmapdev init demo && hmapdev build → dist/demo_bundle.hmap（linux+darwin）
- 本机安装 /usr/local/bin/hmapdev，旧名以软链保留；sdk list/current 正常

tools/hmapdev/templates/main.lua.tmpl

@@ -0,0 +1,45 @@
+local plugin = {
+  name = "{{.Plg.Name}}",
+  tools = {},
+  stages = {},
+  settings = {}
+}
+
+function plugin:start(sdk)
+  sdk.log("{{.Plg.Name}} plugin starting...")
+
+  -- Register a configuration setting
+  -- sdk.settings.register({
+  --   key = "{{.Plg.Name}}.example",
+  --   default = "hello",
+  --   type = "string",
+  --   display_name = "Example Config",
+  --   description = "An example configuration key"
+  -- })
+
+  -- Register a tool
+  local ok = sdk:register_tool("{{.Plg.Name}}_hello", {
+    name = "{{.Plg.Name}}_hello",
+    description = "A hello world tool",
+    parameters = {
+      type = "object",
+      properties = {}
+    }
+  }, function(args)
+    return { content = "Hello from {{.Plg.Name}} plugin!" }
+  end)
+
+  if not ok then
+    sdk.log("error: failed to register tool")
+    return false
+  end
+
+  sdk.log("{{.Plg.Name}} plugin started")
+  return true
+end
+
+function plugin:stop()
+  return true
+end
+
+return plugin