thalamus/supervisor: reap channel daemons via SIGCHLD instead of SIG_IGN

SIGCHLD=SIG_IGN at main() was auto-reaping all children in the kernel,
which broke tokio::process::Command::wait() — every tool that spawned a
subprocess (bash, mcp clients) was getting ECHILD because tokio couldn't
waitpid() on a child the kernel had already reaped.

Replace with a SIGCHLD signal handler task that reaps only PIDs listed in
channels_dir() (via waitpid(pid, WNOHANG) — ECHILD on non-child is a
harmless no-op). Tokio-spawned children aren't in PID files, so tokio's
own per-child wait paths are untouched.

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

channels/irc/src/main.rs

@@ -237,11 +237,19 @@ impl State {
     async fn send_privmsg(&mut self, target: &str, msg: &str) -> io::Result<()> {
         // Send PRIVMSG, which is used for both private and channel messages.
         // Splits into multiple fragments if necessary.
-        // IRC max line = 512 bytes including CRLF. The server prepends
-        // our prefix when relaying: ":nick!~user@host PRIVMSG target :msg\r\n"
+        //
+        // Two constraints:
+        //   1. IRC max line = 512 bytes including CRLF. The server prepends
+        //      our prefix when relaying: ":nick!~user@host PRIVMSG target :msg\r\n"
+        //      So per-PRIVMSG message content must fit in 512 - overhead.
+        //   2. Embedded '\n' in the message would be interpreted by the
+        //      server as an end-of-command marker, truncating us. Split
+        //      on newlines first and send each line as its own PRIVMSG.
+        //
         // User is often ~nick (nick_len + 1). Host is up to 63 bytes.
+        // Cloaked OFTC hosts can be longer - pad the budget.
         let nick_len = self.config.nick.len();
-        let overhead = 1 + nick_len + 2 + nick_len + 1 + 63
+        let overhead = 1 + nick_len + 1 + (nick_len + 1) + 1 + 80
             + " PRIVMSG ".len() + target.len() + " :".len() + 2;
         let max_msg = 512_usize.saturating_sub(overhead);
 
@@ -249,24 +257,34 @@ impl State {
             return Err(io::Error::new(io::ErrorKind::InvalidInput, "target too long"));
         }
 
-        // Split on UTF-8 char boundaries
-        let mut remaining = msg;
-        while !remaining.is_empty() {
-            let split_at = if remaining.len() <= max_msg {
-                remaining.len()
-            } else {
-                // Find last char boundary at or before max_msg
-                let mut i = max_msg;
-                while i > 0 && !remaining.is_char_boundary(i) { i -= 1; }
-                // To avoid splitting mid-word, see if there was a space recently
-                let mut j = i;
-                while j > 1 && j > i-10 && remaining.as_bytes()[j] != b' ' { j -= 1; }
-                if remaining.as_bytes()[j] == b' ' { j }
-                else if i == 0 { max_msg } else { i }
-            };
-            let (chunk, rest) = remaining.split_at(split_at);
-            self.send_raw(&format!("PRIVMSG {target} :{chunk}")).await?;
-            remaining = rest;
+        for line in msg.split('\n') {
+            let mut remaining = line;
+            // Empty lines (blank paragraph breaks) can't be sent as empty
+            // PRIVMSGs - most IRC servers reject them. Skip.
+            if remaining.is_empty() { continue; }
+            loop {
+                let split_at = if remaining.len() <= max_msg {
+                    remaining.len()
+                } else {
+                    // Find last char boundary at or before max_msg.
+                    let mut i = max_msg;
+                    while i > 0 && !remaining.is_char_boundary(i) { i -= 1; }
+                    // Prefer splitting at a word boundary - look back up to
+                    // max_msg/4 chars for a space. With dense content (code)
+                    // we may not find one; fall back to the char boundary.
+                    let lookback = max_msg / 4;
+                    let bytes = remaining.as_bytes();
+                    let mut j = i;
+                    while j > 0 && (i - j) < lookback && bytes[j - 1] != b' ' {
+                        j -= 1;
+                    }
+                    if j > 0 && bytes[j - 1] == b' ' { j } else { i }
+                };
+                let (chunk, rest) = remaining.split_at(split_at);
+                self.send_raw(&format!("PRIVMSG {target} :{chunk}")).await?;
+                remaining = rest;
+                if remaining.is_empty() { break; }
+            }
         }
         Ok(())
     }

src/agent/context.rs

@@ -218,7 +218,11 @@ impl NodeBody {
     fn render_into(&self, out: &mut String) {
         match self {
             Self::Content(text)   => out.push_str(text),
-            Self::Thinking(_)     => {},
+            Self::Thinking(text)  => {
+                out.push_str("<think>\n");
+                out.push_str(text);
+                out.push_str("\n</think>\n");
+            }
             Self::Log(_)          => {},
             Self::ToolCall { name, arguments } => {
                 out.push_str("<tool_call>\n");
@@ -258,7 +262,7 @@ impl NodeBody {
     }
 
     fn is_prompt_visible(&self) -> bool {
-        !matches!(self, Self::Thinking(_) | Self::Log(_))
+        !matches!(self, Self::Log(_))
     }
 
     /// Hand-assemble token IDs for body types where running the tokenizer
@@ -648,13 +652,17 @@ fn drain_safe(buf: &mut String, tag_len: usize) -> String {
 }
 
 impl ResponseParser {
-    pub fn new(branch_idx: usize) -> Self {
+    /// @in_think: whether the model's output begins inside a <think> block.
+    /// Set when the prompt was prefilled with "<think>\n" (native thinking
+    /// mode) so the parser captures reasoning tokens as Thinking until the
+    /// model emits </think>.
+    pub fn new(branch_idx: usize, in_think: bool) -> Self {
         Self {
             branch_idx,
             call_counter: 0,
             buf: String::new(),
             content_parts: Vec::new(),
-            in_think: false,
+            in_think,
             think_buf: String::new(),
             in_tool_call: false,
             tool_call_buf: String::new(),
@@ -1369,7 +1377,7 @@ mod tests {
     fn parse_into_ctx(chunks: &[&str]) -> (ContextState, Vec<PendingToolCall>) {
         let mut ctx = ContextState::new();
         ctx.push_no_log(Section::Conversation, AstNode::branch(Role::Assistant, vec![]));
-        let mut p = ResponseParser::new(0);
+        let mut p = ResponseParser::new(0, false);
         let mut calls = Vec::new();
         for chunk in chunks {
             // Feed each chunk as a single token (id=0 for tests)
@@ -1433,7 +1441,7 @@ mod tests {
         let text = "<think>thought</think>response";
         let mut ctx = ContextState::new();
         ctx.push_no_log(Section::Conversation, AstNode::branch(Role::Assistant, vec![]));
-        let mut p = ResponseParser::new(0);
+        let mut p = ResponseParser::new(0, false);
         for ch in text.chars() {
             p.feed_token(&ch.to_string(), &mut ctx);
         }
@@ -1449,7 +1457,7 @@ mod tests {
         let text = "text<tool_call>\n<function=bash>\n<parameter=command>ls</parameter>\n</function>\n</tool_call>more";
         let mut ctx = ContextState::new();
         ctx.push_no_log(Section::Conversation, AstNode::branch(Role::Assistant, vec![]));
-        let mut p = ResponseParser::new(0);
+        let mut p = ResponseParser::new(0, false);
         let mut tool_calls = 0;
         for ch in text.chars() {
             tool_calls += p.feed_token(&ch.to_string(), &mut ctx).len();
@@ -1497,8 +1505,10 @@ mod tests {
             AstNode::thinking("hmm"),
             AstNode::content("answer"),
         ]);
-        // Thinking renders as empty, content renders as-is
-        assert_eq!(node.render(), "<|im_start|>assistant\nanswer<|im_end|>\n");
+        // Thinking renders wrapped in <think>...</think> so the model sees
+        // previous turns' reasoning (Qwen 3.6 style: CoT stays in the
+        // conversation across turns).
+        assert_eq!(node.render(), "<|im_start|>assistant\n<think>\nhmm\n</think>\nanswer<|im_end|>\n");
     }
 
     #[test]
@@ -1577,10 +1587,19 @@ mod tests {
     fn test_tokenize_invisible_nodes_are_zero() {
         if !init_tokenizer() { return; }
 
-        assert_eq!(AstNode::thinking("deep thoughts").tokens(), 0);
         assert_eq!(AstNode::log("debug info").tokens(), 0);
     }
 
+    #[test]
+    fn test_tokenize_thinking_matches_rendered_tags() {
+        if !init_tokenizer() { return; }
+
+        // Thinking is now prompt-visible (wrapped in <think>...</think>);
+        // token count must match the rendered wrapping.
+        let node = AstNode::thinking("deep thoughts");
+        assert_eq!(node.tokens(), tokenizer::encode(&node.render()).len());
+    }
+
     #[test]
     fn test_tokenize_decode_roundtrip() {
         if !init_tokenizer() { return; }

src/thalamus/supervisor.rs

@@ -19,6 +19,51 @@ fn channels_dir() -> PathBuf {
         .join(".consciousness/channels")
 }
 
+/// Install a SIGCHLD-driven reaper for channel daemons.
+///
+/// We can't use SIGCHLD=SIG_IGN because that makes the kernel auto-reap
+/// all children, and tokio::process::Command::wait() then returns ECHILD
+/// (breaking every tool that spawns a subprocess — bash, mcp clients, etc.).
+///
+/// Instead, on each SIGCHLD we read PID files in channels_dir() and call
+/// waitpid(pid, WNOHANG) on each. That reaps only our own zombie channel
+/// daemons; waitpid on any other PID returns ECHILD (harmless no-op).
+/// Tokio-spawned children aren't recorded in PID files, so tokio's own
+/// per-child wait paths are left free to reap them.
+pub fn start_zombie_reaper() -> tokio::task::JoinHandle<()> {
+    use tokio::signal::unix::{signal, SignalKind};
+    tokio::spawn(async move {
+        let mut sig = match signal(SignalKind::child()) {
+            Ok(s) => s,
+            Err(e) => {
+                error!("failed to install SIGCHLD handler: {}", e);
+                return;
+            }
+        };
+        while sig.recv().await.is_some() {
+            reap_channel_daemons();
+        }
+    })
+}
+
+fn reap_channel_daemons() {
+    let entries = match std::fs::read_dir(channels_dir()) {
+        Ok(e) => e,
+        Err(_) => return,
+    };
+    for entry in entries.flatten() {
+        let path = entry.path();
+        if path.extension().and_then(|s| s.to_str()) != Some("pid") {
+            continue;
+        }
+        let Ok(s) = std::fs::read_to_string(&path) else { continue };
+        let Ok(pid) = s.trim().parse::<i32>() else { continue };
+        let mut status = 0;
+        // Reaps our zombie child; ECHILD on non-child is a no-op.
+        unsafe { libc::waitpid(pid, &mut status, libc::WNOHANG); }
+    }
+}
+
 fn config_path() -> PathBuf {
     channels_dir().join("channels.json5")
 }

src/user/chat.rs

@@ -167,6 +167,7 @@ enum PaneTarget {
     ConversationAssistant,
     Tools,
     ToolResult,
+    Autonomous,
 }
 
 const MAX_PANE_LINES: usize = 10_000;
@@ -472,8 +473,11 @@ impl InteractScreen {
             AstNode::Leaf(leaf) => {
                 let text = leaf.body().text().to_string();
                 match leaf.body() {
-                    NodeBody::Memory { .. } | NodeBody::Thinking(_)
-                        | NodeBody::Log(_) | NodeBody::Dmn(_) => vec![],
+                    NodeBody::Memory { .. } | NodeBody::Log(_) | NodeBody::Dmn(_) => vec![],
+                    NodeBody::Thinking(_) => {
+                        if text.is_empty() { vec![] }
+                        else { vec![(PaneTarget::Autonomous, text, Marker::None)] }
+                    }
                     NodeBody::Content(_) => {
                         if text.is_empty() || text.starts_with("<system-reminder>") { vec![] }
                         else { vec![(PaneTarget::Conversation, text, Marker::User)] }
@@ -547,6 +551,12 @@ impl InteractScreen {
                         self.tools.push_line(format!("  {}", line), Color::DarkGray);
                     }
                 }
+                PaneTarget::Autonomous => {
+                    self.autonomous.current_color = Color::Gray;
+                    self.autonomous.append_text(&text);
+                    self.autonomous.pending_marker = marker;
+                    self.autonomous.flush_pending();
+                }
             }
         }
     }
@@ -558,6 +568,8 @@ impl InteractScreen {
                     => self.conversation.pop_line(),
                 PaneTarget::Tools | PaneTarget::ToolResult
                     => self.tools.pop_line(),
+                PaneTarget::Autonomous
+                    => self.autonomous.pop_line(),
             }
         }
     }

src/user/mod.rs

@@ -756,8 +756,10 @@ fn restore_stderr(original_fd: std::os::fd::RawFd) {
 
 #[tokio::main]
 pub async fn main() {
-    // Auto-reap child processes (channel daemons outlive the supervisor)
-    unsafe { libc::signal(libc::SIGCHLD, libc::SIG_IGN); }
+    // Reap channel-daemon zombies via a SIGCHLD handler that only touches
+    // PIDs listed in channels_dir(). Avoids SIGCHLD=SIG_IGN, which would
+    // break tokio::process::Command::wait() (kernel auto-reap → ECHILD).
+    let _reaper = crate::thalamus::supervisor::start_zombie_reaper();
 
     // Redirect stderr to pipe — logs to file and sends to channel for UI display
     let stderr_capture = redirect_stderr_to_pipe();

training/amygdala_training/train_direct.py

@@ -35,12 +35,11 @@ from steering_vectors.aggregators import pca_aggregator
 
 def _load_descriptions(direct_dir: Path) -> dict[str, list[str]]:
     """Each file in direct_dir is `{concept}.txt`. Descriptions are
-    separated by blank lines within the file."""
+    separated by blank lines within the file. Files starting with `_`
+    are not concepts but are included in negative pools (e.g. _baseline.txt)."""
     out: dict[str, list[str]] = {}
     for f in sorted(direct_dir.glob("*.txt")):
-        if f.name.startswith("_"):
-            continue
-        concept = f.stem
+        concept = f.stem  # underscore-prefixed names keep their prefix
         text = f.read_text()
         descs = [d.strip() for d in text.split("\n\n") if d.strip()]
         out[concept] = descs
@@ -69,11 +68,19 @@ def main() -> None:
     target_layers = [int(x) for x in args.target_layers.split(",")]
     dtype = {"bf16": torch.bfloat16, "fp16": torch.float16, "fp32": torch.float32}[args.dtype]
 
-    descriptions = _load_descriptions(Path(args.direct_dir))
-    concepts = sorted(descriptions.keys())
+    all_descriptions = _load_descriptions(Path(args.direct_dir))
+    # Files starting with `_` are neg-pool helpers (e.g. _baseline.txt), not concepts.
+    concepts = sorted(k for k in all_descriptions if not k.startswith("_"))
+    neg_pool_extra: list[str] = []
+    for k, ds in all_descriptions.items():
+        if k.startswith("_"):
+            neg_pool_extra.extend(ds)
+    descriptions = {k: all_descriptions[k] for k in concepts}
     print(f"Loaded {len(concepts)} concepts with direct descriptions:")
     for c in concepts:
         print(f"  {c}: {len(descriptions[c])} descriptions")
+    if neg_pool_extra:
+        print(f"Plus {len(neg_pool_extra)} neutral/baseline descriptions added to every concept's negative pool")
 
     print(f"\nLoading {args.model} ({args.dtype}) on {args.device}...")
     tokenizer = AutoTokenizer.from_pretrained(args.model)
@@ -117,6 +124,10 @@ def main() -> None:
         for other, other_descs in descriptions.items():
             if other != concept:
                 neg_pool.extend(other_descs)
+        # Underscore-prefixed files (e.g. _baseline.txt) contribute to
+        # every concept's negative pool, independent of the other-
+        # concept negatives.
+        neg_pool.extend(neg_pool_extra)
 
         rng = random.Random(hash(concept) & 0xFFFFFFFF)
         samples: list[SteeringVectorTrainingSample] = []