Default systemPrompt to claude_code preset

Without an explicit systemPrompt, the SDK would use no system prompt.
Now it defaults to the claude_code preset to match CLI behavior.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

base-action/src/parse-sdk-options.ts

@@ -101,7 +101,7 @@ export function parseSdkOptions(options: ClaudeOptions): ParsedSdkOptions {
     env.GITHUB_ACTION_INPUTS = process.env.INPUT_ACTION_INPUTS_PRESENT;
   }
 
-  // Build system prompt option
+  // Build system prompt option - default to claude_code preset
   let systemPrompt: SdkOptions["systemPrompt"];
   if (options.systemPrompt) {
     systemPrompt = options.systemPrompt;
@@ -111,6 +111,12 @@ export function parseSdkOptions(options: ClaudeOptions): ParsedSdkOptions {
       preset: "claude_code",
       append: options.appendSystemPrompt,
     };
+  } else {
+    // Default to claude_code preset when no custom prompt is specified
+    systemPrompt = {
+      type: "preset",
+      preset: "claude_code",
+    };
   }
 
   // Build SDK options - use merged tools from both direct options and claudeArgs
@@ -130,6 +136,9 @@ export function parseSdkOptions(options: ClaudeOptions): ParsedSdkOptions {
     // Note: allowedTools and disallowedTools have been removed from extraArgs to prevent duplicates
     extraArgs,
     env,
+
+    // Load settings from all sources to pick up CLI-installed plugins, CLAUDE.md, etc.
+    settingSources: ["user", "project", "local"],
   };
 
   return {

base-action/src/run-claude-sdk.ts

@@ -75,12 +75,28 @@ export async function runClaudeWithSdk(
   }
 
   console.log(`Running Claude with prompt from file: ${promptPath}`);
+  console.log(
+    "[DEBUG] Prompt content (first 2000 chars):",
+    prompt.substring(0, 2000),
+  );
+  console.log("[DEBUG] Prompt length:", prompt.length);
+  console.log(
+    "[DEBUG] sdkOptions passed to query():",
+    JSON.stringify(sdkOptions, null, 2),
+  );
 
   const messages: SDKMessage[] = [];
   let resultMessage: SDKResultMessage | undefined;
 
   try {
+    console.log("[DEBUG] About to call query()...");
     for await (const message of query({ prompt, options: sdkOptions })) {
+      console.log(
+        "[DEBUG] Received message type:",
+        message.type,
+        "subtype:",
+        (message as any).subtype,
+      );
       messages.push(message);
 
       const sanitized = sanitizeSdkOutput(message, showFullOutput);
@@ -90,8 +106,16 @@ export async function runClaudeWithSdk(
 
       if (message.type === "result") {
         resultMessage = message as SDKResultMessage;
+        console.log(
+          "[DEBUG] Got result message:",
+          JSON.stringify(resultMessage, null, 2),
+        );
       }
     }
+    console.log(
+      "[DEBUG] Finished iterating query(), total messages:",
+      messages.length,
+    );
   } catch (error) {
     console.error("SDK execution error:", error);
     core.setOutput("conclusion", "failure");

base-action/src/run-claude.ts

@@ -174,7 +174,15 @@ export async function runClaude(promptPath: string, options: ClaudeOptions) {
   );
 
   if (useAgentSdk) {
+    console.log(
+      "[DEBUG] Raw options passed to SDK path:",
+      JSON.stringify(options, null, 2),
+    );
     const parsedOptions = parseSdkOptions(options);
+    console.log(
+      "[DEBUG] Parsed SDK options:",
+      JSON.stringify(parsedOptions, null, 2),
+    );
     return runClaudeWithSdk(promptPath, parsedOptions);
   }