add context window monitor

Writes the current context window to logs/current_context_window (uses a symlink to a session ID).

This PR was unfortunately generated by a different LLM and did a ton of superficial reformating, it's actually a fairly small and benign change, but I don't want to roll back everything. Hope that's ok.

crates/g3-console/examples/debug_detector.rs

@@ -1,19 +1,19 @@
-use sysinfo::{System, Pid};
+use sysinfo::{Pid, System};
 
 fn main() {
     let mut sys = System::new_all();
     sys.refresh_processes();
-    
+
     println!("Looking for g3 processes...");
-    
+
     for (pid, process) in sys.processes() {
         let cmd = process.cmd();
         if cmd.is_empty() {
             continue;
         }
-        
+
         let cmd_str = cmd.join(" ");
-        
+
         // Check if this contains 'g3'
         if cmd_str.contains("g3") {
             println!("\nFound potential g3 process:");
@@ -21,15 +21,15 @@ fn main() {
             println!("  Name: {}", process.name());
             println!("  Cmd[0]: {:?}", cmd.get(0));
             println!("  Full cmd: {:?}", cmd);
-            
+
             // Check detection logic
             let is_g3_binary = cmd.get(0).map(|s| s.ends_with("g3")).unwrap_or(false);
             let is_cargo_run = cmd.get(0).map(|s| s.contains("cargo")).unwrap_or(false)
                 && cmd.iter().any(|s| s == "run" || s.contains("g3"));
-            
+
             println!("  is_g3_binary: {}", is_g3_binary);
             println!("  is_cargo_run: {}", is_cargo_run);
-            
+
             // Check workspace
             let has_workspace = cmd.iter().any(|s| s == "--workspace" || s == "-w");
             println!("  has_workspace: {}", has_workspace);