fix: Auto-detect JSON Lines output format for Codex CLI

Problem: Codex CLI uses --json flag to output JSONL events, but executor was using plain text parser. This prevented proper parsing of structured events, breaking session creation.

Root cause: buildCommand() added --json flag for Codex but never communicated this to the output parser. Result: JSONL events treated as raw text → session markers lost.

Solution:
- Extend buildCommand() to return outputFormat
- Auto-detect 'json-lines' when tool is 'codex'
- Use auto-detected format in executeCliTool()
- Properly parse structured events and extract session data

Files modified:
- ccw/src/tools/cli-executor-utils.ts: Add output format auto-detection
- ccw/src/tools/cli-executor-core.ts: Use auto-detected format for parser
- ccw/src/commands/cli.ts: Add debug instrumentation

Verified:
- Codex outputs valid JSONL (confirmed via direct test)
- CLI_EXECUTION_STARTED events broadcast correctly
- Issue was downstream in output parsing, not event transmission

ccw/src/tools/cli-executor-utils.ts

@@ -166,7 +166,7 @@ export function buildCommand(params: {
     commit?: string;
     title?: string;
   };
-}): { command: string; args: string[]; useStdin: boolean } {
+}): { command: string; args: string[]; useStdin: boolean; outputFormat?: 'text' | 'json-lines' } {
   const { tool, prompt, mode = 'analysis', model, dir, include, nativeResume, settingsFile, reviewOptions } = params;
 
   debugLog('BUILD_CMD', `Building command for tool: ${tool}`, {
@@ -381,5 +381,8 @@ export function buildCommand(params: {
     fullCommand: `${command} ${args.join(' ')}${useStdin ? ' (stdin)' : ''}`,
   });
 
-  return { command, args, useStdin };
+  // Auto-detect output format: Codex uses --json flag for JSONL output
+  const outputFormat = tool.toLowerCase() === 'codex' ? 'json-lines' : 'text';
+
+  return { command, args, useStdin, outputFormat };
 }