fix(kiro): deliver system prompt natively, add Opus 4.5/4.7/4.8, tolerate dash version ids (#2366)

- Pass system prompt via native systemInstruction field (+ <instructions> fallback)
  so Claude models stop treating it as info-only <system-reminder>
- Add Opus 4.5/4.7/4.8 (base/thinking/agentic/thinking+agentic) to Kiro registry
- normalizeModelId(): dash->dot version separator, scoped to Kiro provider only
- Replace <system-reminder> with <instructions> in claude-to-openai/openai-to-kiro

Co-authored-by: Cursor <cursoragent@cursor.com>

open-sse/translator/request/claude-to-kiro.js

@@ -404,7 +404,10 @@ export function claudeToKiroRequest(model, body, stream, credentials) {
 
   let finalContent = currentMessage?.userInputMessage?.content || "";
 
-  // System prompt → prepend to the user content.
+  // System prompt: pass via native systemInstruction field (Kiro/Q API supports it)
+  // and also prepend as <instructions> in user content as fallback for upstreams
+  // that don't support the native field.
+  let systemInstruction = undefined;
   if (body.system) {
     let systemText = "";
     if (typeof body.system === "string") {
@@ -412,7 +415,10 @@ export function claudeToKiroRequest(model, body, stream, credentials) {
     } else if (Array.isArray(body.system)) {
       systemText = body.system.map((s) => s.text || "").join("\n");
     }
-    if (systemText) finalContent = `${systemText}\n\n${finalContent}`;
+    if (systemText) {
+      systemInstruction = systemText;
+      finalContent = `<instructions>\n${systemText}\n</instructions>\n\n${finalContent}`;
+    }
   }
 
   // Prefix order: thinking_mode tag, timestamp marker, then agentic prompt.
@@ -423,23 +429,29 @@ export function claudeToKiroRequest(model, body, stream, credentials) {
   if (agentic) prefixParts.push(KIRO_AGENTIC_SYSTEM_PROMPT);
   finalContent = `${prefixParts.join("\n\n")}\n\n${finalContent}`;
 
+  const userInputMessage = {
+    content: finalContent,
+    modelId: upstreamModel,
+    origin: "AI_EDITOR",
+    ...(currentMessage?.userInputMessage?.userInputMessageContext && {
+      userInputMessageContext:
+        currentMessage.userInputMessage.userInputMessageContext,
+    }),
+    ...(currentMessage?.userInputMessage?.images && {
+      images: currentMessage.userInputMessage.images,
+    }),
+  };
+
+  if (systemInstruction) {
+    userInputMessage.systemInstruction = systemInstruction;
+  }
+
   const payload = {
     conversationState: {
       chatTriggerType: "MANUAL",
       conversationId: uuidv4(),
       currentMessage: {
-        userInputMessage: {
-          content: finalContent,
-          modelId: upstreamModel,
-          origin: "AI_EDITOR",
-          ...(currentMessage?.userInputMessage?.userInputMessageContext && {
-            userInputMessageContext:
-              currentMessage.userInputMessage.userInputMessageContext,
-          }),
-          ...(currentMessage?.userInputMessage?.images && {
-            images: currentMessage.userInputMessage.images,
-          }),
-        },
+        userInputMessage,
       },
       history,
     },

open-sse/translator/request/claude-to-openai.js

@@ -129,14 +129,15 @@ function fixMissingToolResponsesOpenAI(messages) {
   }
 }
 
-// Wrap mid-conversation system text so it ends as a user turn (avoids Anthropic prefill 400)
+// Wrap mid-conversation system text so it ends as a user turn (avoids Anthropic prefill 400).
+// Uses <instructions> tags that Claude models treat as authoritative directives.
 function systemReminderText(content) {
   const parts = Array.isArray(content)
     ? content.filter(c => c?.type === CLAUDE_BLOCK.TEXT).map(c => c.text || "")
     : [typeof content === "string" ? content : ""];
   const text = parts.filter(Boolean).join("\n");
   if (!text.trim()) return "";
-  return `<system-reminder>\n${text}\n</system-reminder>`;
+  return `<instructions>\n${text}\n</instructions>`;
 }
 
 // Convert single Claude message - returns single message or array of messages

open-sse/translator/request/openai-to-kiro.js

@@ -270,6 +270,7 @@ function convertMessages(messages, tools, model) {
     let role = msg.role;
 
     // Normalize: system/tool -> user
+    const wasSystem = role === ROLE.SYSTEM;
     if (role === ROLE.SYSTEM || role === ROLE.TOOL) {
       role = ROLE.USER;
     }
@@ -338,7 +339,10 @@ function convertMessages(messages, tools, model) {
           content: [{ text: toolContent }]
         });
       } else if (content) {
-        pendingUserContent.push(content);
+        // <instructions> tags: Claude models treat these as authoritative directives.
+        pendingUserContent.push(
+          wasSystem ? `<instructions>\n${content}\n</instructions>` : content
+        );
       }
     } else if (role === ROLE.ASSISTANT) {
       // Extract text content and tool uses