fix: set CLAUDE_CODE_ENTRYPOINT for SDK path to match CLI path (#791)

Previously, the SDK path would result in the CLI setting the entrypoint
to 'sdk-ts' internally, while the non-SDK (CLI) path would correctly
set it to 'claude-code-github-action' based on the CLAUDE_CODE_ACTION
env var.

This change explicitly sets CLAUDE_CODE_ENTRYPOINT in both:
1. The action.yml env block (for consistency)
2. The SDK options env (to override the CLI's internal default)

The CLI respects pre-set entrypoint values, so this ensures consistent
user agent reporting for both execution paths.

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

Co-authored-by: Claude <[email protected]>

Author: ashwin-ant

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

@@ -212,6 +212,8 @@ export function parseSdkOptions(options: ClaudeOptions): ParsedSdkOptions {
   if (process.env.INPUT_ACTION_INPUTS_PRESENT) {
     env.GITHUB_ACTION_INPUTS = process.env.INPUT_ACTION_INPUTS_PRESENT;
   }
+  // Ensure SDK path uses the same entrypoint as the CLI path
+  env.CLAUDE_CODE_ENTRYPOINT = "claude-code-github-action";
 
   // Build system prompt option - default to claude_code preset
   let systemPrompt: SdkOptions["systemPrompt"];