fix: extract --max-turns from claude_args for SDK turn limit

The SDK enforces its own maxTurns counter independently of CLI flags.
When --max-turns is passed via claude_args, it lands in extraArgs and
reaches the CLI, but the SDK cuts off execution at its own default (10)
before the CLI can act on it.

Extract --max-turns from extraArgs into sdkOptions.maxTurns, following
the same pattern used for allowedTools and disallowedTools. The direct
max_turns input takes precedence when both are set.

Fixes #1177

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

Author: qozle

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

@@ -253,11 +253,19 @@ export function parseSdkOptions(options: ClaudeOptions): ParsedSdkOptions {
     };
   }
 
+  // Extract --max-turns from extraArgs so it sets sdkOptions.maxTurns (the SDK
+  // enforces its own turn counter, so passing it only via extraArgs doesn't work)
+  const maxTurnsFromArgs = extraArgs["max-turns"] ?? extraArgs["maxTurns"];
+  delete extraArgs["max-turns"];
+  delete extraArgs["maxTurns"];
+  const maxTurnsRaw = options.maxTurns || maxTurnsFromArgs;
+  const maxTurns = maxTurnsRaw ? parseInt(maxTurnsRaw, 10) : undefined;
+
   // Build SDK options - use merged tools from both direct options and claudeArgs
   const sdkOptions: SdkOptions = {
     // Direct options from ClaudeOptions inputs
     model: options.model,
-    maxTurns: options.maxTurns ? parseInt(options.maxTurns, 10) : undefined,
+    maxTurns: Number.isFinite(maxTurns) ? maxTurns : undefined,
     allowedTools:
       mergedAllowedTools.length > 0 ? mergedAllowedTools : undefined,
     disallowedTools: