check for stale TODOs

on by default, can be disabled

crates/g3-cli/src/lib.rs

@@ -164,6 +164,7 @@ use rustyline::error::ReadlineError;
 use rustyline::DefaultEditor;
 use std::path::Path;
 use std::path::PathBuf;
+use sha2::{Digest, Sha256};
 use tokio_util::sync::CancellationToken;
 use tracing::{error, info};
 
@@ -1660,6 +1661,17 @@ async fn run_autonomous(
     } else {
         output.print("📋 Requirements loaded from requirements.md");
     }
+
+    // Calculate SHA256 of requirements
+    let mut hasher = Sha256::new();
+    hasher.update(requirements.as_bytes());
+    let requirements_sha = hex::encode(hasher.finalize());
+    
+    output.print(&format!("🔒 Requirements SHA256: {}", requirements_sha));
+    
+    // Pass SHA to agent for staleness checking
+    agent.set_requirements_sha(requirements_sha.clone());
+
     output.print("🔄 Starting coach-player feedback loop...");
 
     // Check if implementation files already exist
@@ -1692,8 +1704,8 @@ async fn run_autonomous(
             // Player mode: implement requirements (with coach feedback if available)
             let player_prompt = if coach_feedback.is_empty() {
                 format!(
-                    "You are G3 in implementation mode. Read and implement the following requirements:\n\n{}\n\nImplement this step by step, creating all necessary files and code.",
-                    requirements
+                    "You are G3 in implementation mode. Read and implement the following requirements:\n\n{}\n\nRequirements SHA256: {}\n\nImplement this step by step, creating all necessary files and code.",
+                    requirements, requirements_sha
                 )
             } else {
                 format!(

crates/g3-cli/src/machine_ui_writer.rs

@@ -91,4 +91,11 @@ impl UiWriter for MachineUiWriter {
     fn wants_full_output(&self) -> bool {
         true  // Machine mode wants complete, untruncated output
     }
+
+    fn prompt_user_yes_no(&self, message: &str) -> bool {
+        // In machine mode, we can't interactively prompt, so we log the request and return true
+        // to allow automation to proceed.
+        println!("PROMPT_USER_YES_NO: {}", message);
+        true
+    }
 }

crates/g3-cli/src/ui_writer_impl.rs

@@ -343,5 +343,18 @@ impl UiWriter for ConsoleUiWriter {
     fn flush(&self) {
         let _ = io::stdout().flush();
     }
+
+    fn prompt_user_yes_no(&self, message: &str) -> bool {
+        print!("{} [y/N] ", message);
+        let _ = io::stdout().flush();
+
+        let mut input = String::new();
+        if io::stdin().read_line(&mut input).is_ok() {
+            let trimmed = input.trim().to_lowercase();
+            trimmed == "y" || trimmed == "yes"
+        } else {
+            false
+        }
+    }
 }