fix(plugin-sdk): keep shipped ErrorKind/detectErrorKind as deprecated compat

The latest stable package exposes both names via the deprecated
openclaw/plugin-sdk/infra-runtime subpath. Compat now lives in the barrel
itself with the old substring semantics and a removal plan; core runtime no
longer uses them. Also converts the chat mapping switch to an if-chain for
switch-exhaustiveness lint.

src/gateway/server-chat.ts

@@ -243,12 +243,12 @@ export function resolveChatErrorKindFromError(error: unknown): ChatErrorKind | u
   ) {
     return "refusal";
   }
-  switch (resolveFailoverReasonFromError(error)) {
-    case "rate_limit":
-    case "overloaded":
-      return "rate_limit";
-    case "context_overflow":
-      return "context_length";
+  const reason = resolveFailoverReasonFromError(error);
+  if (reason === "rate_limit" || reason === "overloaded") {
+    return "rate_limit";
+  }
+  if (reason === "context_overflow") {
+    return "context_length";
   }
   // FailoverReason "timeout" is the retryable-transient bucket and deliberately
   // swallows generic 5xx; only genuinely timeout-shaped errors get the badge.

src/plugin-sdk/infra-runtime.ts

@@ -19,6 +19,52 @@ export {
 export * from "../infra/diagnostic-flags.js";
 export * from "../infra/env.js";
 export * from "../infra/errors.js";
+import { extractErrorCode, formatErrorMessage } from "../infra/errors.js";
+
+/** @deprecated Shipped compat only (removed from core in #104546); no core caller. Removal with the next plugin-SDK major. */
+export type ErrorKind = "refusal" | "timeout" | "rate_limit" | "context_length" | "unknown";
+
+/**
+ * @deprecated Shipped compat only; preserves the old substring semantics for
+ * external plugins. Core chat classification now maps canonical failover
+ * reasons (see gateway resolveChatErrorKindFromError). Removal with the next
+ * plugin-SDK major.
+ */
+export function detectErrorKind(err: unknown): ErrorKind | undefined {
+  if (err === undefined) {
+    return undefined;
+  }
+  const message = formatErrorMessage(err).toLowerCase();
+  const code = extractErrorCode(err)?.toLowerCase();
+  if (
+    message.includes("refusal") ||
+    message.includes("content_filter") ||
+    message.includes("sensitive") ||
+    message.includes("unhandled stop reason: refusal_policy")
+  ) {
+    return "refusal";
+  }
+  if (
+    message.includes("rate limit") ||
+    message.includes("too many requests") ||
+    message.includes("429") ||
+    code === "429"
+  ) {
+    return "rate_limit";
+  }
+  if (message.includes("timeout") || code === "etimedout" || code === "timeout") {
+    return "timeout";
+  }
+  if (
+    message.includes("context length") ||
+    message.includes("too many tokens") ||
+    message.includes("token limit") ||
+    message.includes("context_window")
+  ) {
+    return "context_length";
+  }
+  return undefined;
+}
 export * from "../infra/exec-approval-command-display.ts";
 export * from "../infra/exec-approval-channel-runtime.ts";
 export * from "../infra/exec-approval-reply.ts";