refactor: centralize ABI metadata into internal/meta/meta.go

- internal/meta/meta.go: add ABIVersion, ABIVersionMin, 45 dispatch
  method IDs, SDKCompatibleVersion (single source of truth)
- internal/plugin/cabi/types.go: re-export from meta.go
- internal/plugin/cabi/loader.go: reject plugin when version > ABIVersion;
  pass ABIVersion in Start instead of hardcoded 1
- loader.{go,c}: comments reference meta.go as canonical

internal/meta/meta.go

@@ -1,5 +1,7 @@
 // Package meta 收集 HomeAgent 内核的全部元数据。
 // 版本号通过 `go build -ldflags` 注入，默认值为 dev 版本。
+// 此文件是 ABI 版本号与 dispatch method ID 的唯一数据源。
+// SDK 仓的 meta/meta.go 应与此保持同步。
 package meta
 
 var (
@@ -15,9 +17,70 @@ var (
 
 	// KernelName 是内核名称。
 	KernelName = "HomeAgent"
+
+	// SDKCompatibleVersion 是此内核兼容的最低 SDK 版本（semver）。
+	SDKCompatibleVersion = "0.8.0"
 )
 
 // FullVersion 返回完整的版本字符串。
 func FullVersion() string {
 	return KernelName + " v" + Version + " (" + Commit + ")"
 }
+
+// ---- ABI 版本（C ABI 协议版本，插件与内核通信用） ----
+
+const (
+	ABIVersion    = 1
+	ABIVersionMin = 1
+)
+
+// ---- Dispatch Method IDs ----
+// 核心→插件：这些 ID 通过 CoreAPI.dispatch 传递，标识 SDK 调用。
+// 插件端的 C enum 定义在 plugindev 的 C ABI header 模板中。
+const (
+	CoreRegisterTool          = 1
+	CoreRegisterStage         = 2
+	CoreRegisterOutputCh      = 3
+	CoreRegisterPluginAPI     = 4
+	CoreInjectText            = 5
+	CoreInjectInterruptText   = 6
+	CoreInjectTextNoMemory    = 7
+	CoreSetAutoRestart        = 8
+	CoreMemoryRecall          = 9
+	CoreMemoryCommit          = 10
+	CoreMemoryIntrospect      = 11
+	CoreMemoryMerge           = 12
+	CoreMemoryPurge           = 13
+	CoreDocQuery              = 14
+	CoreKnowledgeSearch       = 15
+	CoreSettingsGet           = 16
+	CoreSettingsSet           = 17
+	CoreSettingsRegisterDef   = 18
+	CoreLLMListSources        = 19
+	CoreLLMSetSource          = 20
+	CoreSocialGetPerson       = 21
+	CoreSocialGetNetwork      = 22
+	CoreSubscribe             = 23
+	CoreUnsubscribe           = 24
+	CoreFreeString            = 25
+	CoreSettingsGetCore       = 26
+	CoreSettingsSetCore       = 27
+	CoreSettingsListCore      = 28
+	CoreSettingsGetPlugin     = 29
+	CoreSettingsSetPlugin     = 30
+	CoreSettingsListPlugin    = 31
+	CoreDocInsert             = 32
+	CoreDocRemove             = 33
+	CoreDocStats              = 34
+	CoreKnowledgeAdd          = 35
+	CoreKnowledgeList         = 36
+	CoreLLMCurrentSource      = 37
+	CoreSocialGetTrait        = 38
+	CoreSocialGetRelations    = 39
+	CoreSocialListPersons     = 40
+	CoreTextMemoryAppend      = 41
+	CoreSettingsList          = 42
+	CoreSettingsDefs          = 43
+	CoreSettingsDump          = 44
+	CoreSettingsPlugins       = 45
+)