feat: add source file execution and fix function name reference

- Add support for running CLI from TypeScript source when using tsx or similar tools
- Fix outdated happy__change_title reference to hapi__change_title in codex prompt

cli/src/codex/runCodex.ts

@@ -623,7 +623,7 @@ export async function runCodex(opts: {
 
                 if (!wasCreated) {
                     const startConfig: CodexSessionConfig = {
-                        prompt: first ? message.message + '\n\n' + trimIdent(`Based on this message, call functions.happy__change_title to change chat session title that would represent the current task. If chat idea would change dramatically - call this function again to update the title.`) : message.message,
+                        prompt: first ? message.message + '\n\n' + trimIdent(`Based on this message, call functions.hapi__change_title to change chat session title that would represent the current task. If chat idea would change dramatically - call this function again to update the title.`) : message.message,
                         sandbox,
                         'approval-policy': approvalPolicy,
                         config: { mcp_servers: mcpServers }

cli/src/utils/spawnHappyCLI.ts

@@ -102,6 +102,16 @@ export function getHappyCliCommand(args: string[]): HappyCliCommand {
   const isBunRuntime = Boolean((process.versions as Record<string, string | undefined>).bun);
   const entrypoint = isBunRuntime ? resolveEntrypointForBun(projectRoot) : distEntrypoint;
 
+  const argv1 = process.argv[1] ?? '';
+  const runningFromSource = argv1.endsWith(join('src', 'index.ts')) || process.execArgv.some((arg) => arg.includes('tsx'));
+  const srcEntrypoint = join(projectRoot, 'src', 'index.ts');
+  if (!isBunRuntime && runningFromSource && existsSync(srcEntrypoint)) {
+    return {
+      command: process.execPath,
+      args: [...process.execArgv, srcEntrypoint, ...args]
+    };
+  }
+
   const spawnArgs = isBunRuntime ? [entrypoint, ...args] : [
     '--no-warnings',
     '--no-deprecation',