thalamus: interactive sampling parameter controls

F5 screen now shows temperature, top_p, top_k with interactive
adjustment:
- Up/down: select parameter
- Left/right: adjust value (0.05 steps for temp/top_p, 5 for top_k)
- Updates Agent and display immediately via HotkeyAction

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

src/mind/mod.rs

@@ -928,6 +928,16 @@ pub async fn run(cli: crate::user::CliArgs) -> Result<()> {
                 HotkeyAction::KillProcess => session.kill_processes().await,
                 HotkeyAction::Interrupt => session.interrupt().await,
                 HotkeyAction::CycleAutonomy => session.cycle_autonomy(),
+                HotkeyAction::AdjustSampling(param, delta) => {
+                    if let Ok(mut agent) = session.agent.try_lock() {
+                        match param {
+                            0 => { agent.temperature = (agent.temperature + delta).clamp(0.0, 2.0); app.temperature = agent.temperature; }
+                            1 => { agent.top_p = (agent.top_p + delta).clamp(0.0, 1.0); app.top_p = agent.top_p; }
+                            2 => { agent.top_k = (agent.top_k as f32 + delta).max(0.0) as u32; app.top_k = agent.top_k; }
+                            _ => {}
+                        }
+                    }
+                }
             }
         }
 

src/user/mod.rs

@@ -242,6 +242,9 @@ pub enum Screen {
 #[derive(Debug)]
 pub enum HotkeyAction {
     CycleReasoning, KillProcess, Interrupt, CycleAutonomy,
+    /// Adjust a sampling parameter: (param_index, delta)
+    /// 0=temperature, 1=top_p, 2=top_k
+    AdjustSampling(usize, f32),
 }
 
 #[derive(Clone)]
@@ -296,6 +299,8 @@ pub struct App {
     pub(crate) agent_state: Vec<crate::subconscious::subconscious::AgentSnapshot>,
     pub(crate) channel_status: Vec<ChannelStatus>,
     pub(crate) idle_info: Option<IdleInfo>,
+    /// Thalamus screen: selected sampling param (0=temp, 1=top_p, 2=top_k).
+    pub(crate) sampling_selected: usize,
 }
 
 impl App {
@@ -326,7 +331,7 @@ impl App {
             debug_expanded: std::collections::HashSet::new(),
             context_info: None, shared_context,
             agent_selected: 0, agent_log_view: false, agent_state: Vec::new(),
-            channel_status: Vec::new(), idle_info: None,
+            channel_status: Vec::new(), idle_info: None, sampling_selected: 0,
         }
     }
 
@@ -477,7 +482,7 @@ impl App {
                     _ => {}
                 }
             }
-            Screen::Unconscious | Screen::Thalamus => {
+            Screen::Unconscious => {
                 match key.code {
                     KeyCode::PageUp => { self.debug_scroll = self.debug_scroll.saturating_sub(10); return; }
                     KeyCode::PageDown => { self.debug_scroll += 10; return; }
@@ -485,6 +490,34 @@ impl App {
                     _ => {}
                 }
             }
+            Screen::Thalamus => {
+                match key.code {
+                    KeyCode::Up => { self.sampling_selected = self.sampling_selected.saturating_sub(1); return; }
+                    KeyCode::Down => { self.sampling_selected = (self.sampling_selected + 1).min(2); return; }
+                    KeyCode::Right => {
+                        let delta = match self.sampling_selected {
+                            0 => 0.05,  // temperature
+                            1 => 0.05,  // top_p
+                            2 => 5.0,   // top_k
+                            _ => 0.0,
+                        };
+                        self.hotkey_actions.push(HotkeyAction::AdjustSampling(self.sampling_selected, delta));
+                        return;
+                    }
+                    KeyCode::Left => {
+                        let delta = match self.sampling_selected {
+                            0 => -0.05,
+                            1 => -0.05,
+                            2 => -5.0,
+                            _ => 0.0,
+                        };
+                        self.hotkey_actions.push(HotkeyAction::AdjustSampling(self.sampling_selected, delta));
+                        return;
+                    }
+                    KeyCode::Esc => { self.screen = Screen::Interact; return; }
+                    _ => {}
+                }
+            }
             Screen::Interact => {}
         }
 

src/user/thalamus.rs

@@ -48,12 +48,23 @@ impl App {
         }
         lines.push(Line::raw(""));
 
-        // Sampling parameters
-        lines.push(Line::styled("── Sampling ──", section));
+        // Sampling parameters (↑/↓ select, ←/→ adjust)
+        lines.push(Line::styled("── Sampling (←/→ adjust) ──", section));
         lines.push(Line::raw(""));
-        lines.push(Line::raw(format!("  temperature: {:.2}", self.temperature)));
-        lines.push(Line::raw(format!("  top_p:       {:.2}", self.top_p)));
-        lines.push(Line::raw(format!("  top_k:       {}", self.top_k)));
+        let params = [
+            format!("temperature: {:.2}", self.temperature),
+            format!("top_p:       {:.2}", self.top_p),
+            format!("top_k:       {}", self.top_k),
+        ];
+        for (i, label) in params.iter().enumerate() {
+            let prefix = if i == self.sampling_selected { "▸ " } else { "  " };
+            let style = if i == self.sampling_selected {
+                Style::default().fg(Color::Cyan)
+            } else {
+                Style::default()
+            };
+            lines.push(Line::styled(format!("{}{}", prefix, label), style));
+        }
         lines.push(Line::raw(""));
 
         // Channel status from cached data