feat: add human-readable CI log output for show_full_output mode

Replace raw JSON dumps with concise, scannable log lines when
show_full_output is enabled. Adds an onMessage callback to the SDK
runner that formats each message type into 1-2 line summaries with
emoji prefixes, tool-specific parameter display, result correlation
for parallel tool calls, and subagent progress tracking.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

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

@@ -136,6 +136,7 @@ function sanitizeSdkOutput(
 export async function runClaudeWithSdk(
   promptPath: string,
   { sdkOptions, showFullOutput, hasJsonSchema }: ParsedSdkOptions,
+  onMessage?: (message: SDKMessage) => void,
 ): Promise<ClaudeRunResult> {
   // Create prompt configuration - may be a string or multi-block message
   const prompt = await createPromptConfig(promptPath, showFullOutput);
@@ -161,9 +162,13 @@ export async function runClaudeWithSdk(
     for await (const message of query({ prompt, options: sdkOptions })) {
       messages.push(message);
 
-      const sanitized = sanitizeSdkOutput(message, showFullOutput);
-      if (sanitized) {
-        console.log(sanitized);
+      if (onMessage) {
+        onMessage(message);
+      } else {
+        const sanitized = sanitizeSdkOutput(message, showFullOutput);
+        if (sanitized) {
+          console.log(sanitized);
+        }
       }
 
       if (message.type === "result") {