refactor(g3-cli): extract functions from lib.rs to appropriate modules

- Move run_flock_mode() to autonomous.rs (parallel execution mode belongs with autonomous code)
- Move initialize_logging() to utils.rs (utility function with simple bool parameter)
- lib.rs reduced from 274 to 216 lines

No behavior changes. All 28 unit tests pass.

Agent: fowler

crates/g3-cli/src/autonomous.rs

@@ -1,4 +1,4 @@
-//! Autonomous mode for G3 CLI - coach-player feedback loop.
+//! Autonomous mode for G3 CLI - coach-player feedback loop and flock mode.
 
 use anyhow::Result;
 use sha2::{Digest, Sha256};
@@ -694,6 +694,37 @@ fn print_panic_report(
     output.print(&"=".repeat(60));
 }
 
+/// Run flock mode - parallel multi-agent development
+pub async fn run_flock_mode(
+    project_dir: PathBuf,
+    flock_workspace: PathBuf,
+    num_segments: usize,
+    max_turns: usize,
+) -> Result<()> {
+    let output = SimpleOutput::new();
+
+    output.print("");
+    output.print("🦅 G3 FLOCK MODE - Parallel Multi-Agent Development");
+    output.print("");
+    output.print(&format!("📁 Project: {}", project_dir.display()));
+    output.print(&format!("🗂️  Workspace: {}", flock_workspace.display()));
+    output.print(&format!("🔢 Segments: {}", num_segments));
+    output.print(&format!("🔄 Max Turns per Segment: {}", max_turns));
+    output.print("");
+
+    let config = g3_ensembles::FlockConfig::new(project_dir, flock_workspace, num_segments)?
+        .with_max_turns(max_turns);
+
+    let mut flock = g3_ensembles::FlockMode::new(config)?;
+
+    match flock.run().await {
+        Ok(_) => output.print("\n✅ Flock mode completed successfully"),
+        Err(e) => output.print(&format!("\n❌ Flock mode failed: {}", e)),
+    }
+
+    Ok(())
+}
+
 fn print_final_report(
     output: &SimpleOutput,
     agent: &Agent<ConsoleUiWriter>,