Add parser debug logging (POC_DEBUG=1)

Logs full text length, <tool_call> tag count, and tool call details
on stream completion. Helps diagnose parsing issues with subconscious
agents.

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

src/agent/context.rs

@@ -490,15 +490,39 @@ impl ResponseParser {
         let (tx, rx) = tokio::sync::mpsc::unbounded_channel();
         let handle = tokio::spawn(async move {
             let mut parser = self;
+            let debug = std::env::var("POC_DEBUG").is_ok();
+            let mut full_text = String::new();
             while let Some(event) = stream.recv().await {
                 match event {
                     super::api::StreamToken::Token { text, id } => {
+                        full_text.push_str(&text);
                         let mut ctx = agent.context.lock().await;
-                        for call in parser.feed_token(&text, id, &mut ctx) {
+                        let calls = parser.feed_token(&text, id, &mut ctx);
+                        if !calls.is_empty() && debug {
+                            for c in &calls {
+                                eprintln!("[parser] tool_call: {} args={}",
+                                    c.name, &c.arguments[..c.arguments.len().min(80)]);
+                            }
+                        }
+                        for call in calls {
                             let _ = tx.send(call);
                         }
                     }
                     super::api::StreamToken::Done { usage } => {
+                        if debug {
+                            let tc_count = full_text.matches("<tool_call>").count();
+                            eprintln!("[parser] done: {} chars, {} <tool_call> tags",
+                                full_text.len(), tc_count);
+                            if tc_count > 0 {
+                                // Log the raw text around tool calls for debugging
+                                for (i, part) in full_text.split("<tool_call>").enumerate() {
+                                    if i > 0 {
+                                        eprintln!("[parser] tool_call text: {}...",
+                                            &part[..part.len().min(200)]);
+                                    }
+                                }
+                            }
+                        }
                         if let Some(u) = usage {
                             agent.state.lock().await.last_prompt_tokens = u.prompt_tokens;
                         }

src/agent/oneshot.rs

@@ -112,7 +112,6 @@ impl AutoAgent {
         }
     }
 
-    /// Run standalone — TODO: needs rewrite to use completions API
     pub async fn run(
         &mut self,
         _bail_fn: Option<&(dyn Fn(usize) -> Result<(), String> + Sync)>,