feat: centralize default constants and refactor overlay enter handling in TUI

apps/domain/src/agent/defaults.rs

@@ -0,0 +1,34 @@
+//! Shared default constants used across the application.
+//!
+//! Centralising these values eliminates the hardcoded-string duplication
+//! that existed when every call site provided its own inline fallback.
+//! Consumers should reference these constants rather than repeating
+//! the string literals.
+
+/// Default LLM provider API base URL.
+pub const DEFAULT_API_BASE: &str = "https://opencode.ai/zen/v1";
+
+/// Default LLM model identifier.
+pub const DEFAULT_MODEL: &str = "deepseek-v4-flash-free";
+
+/// Fallback JWT secret used only when `JWT_SECRET` env var is unset.
+/// In production this MUST be configured via environment variable.
+pub const FALLBACK_JWT_SECRET: &str = "dev-secret";
+
+/// Default context window size (128k tokens).
+pub const DEFAULT_CONTEXT_WINDOW: usize = 256_000;
+
+/// Maximum tool-call iterations per agent turn.
+pub const MAX_TOOL_ITERATIONS: u32 = 50;
+
+/// Maximum subagent tool-call iterations.
+pub const MAX_SUBAGENT_ITERATIONS: u32 = 25;
+
+/// Default LLM request max tokens.
+pub const DEFAULT_MAX_TOKENS: u32 = 4096;
+
+/// Default temperature for the main agent.
+pub const DEFAULT_TEMPERATURE: f64 = 0.7;
+
+/// Default temperature for compaction / summary calls.
+pub const DEFAULT_COMPACT_TEMPERATURE: f64 = 0.3;

apps/domain/src/agent/mod.rs

@@ -6,6 +6,7 @@ use std::path::PathBuf;
 
 use crate::core::{ChatMessage, ToolCallResult, UsageStats};
 
+pub mod defaults;
 pub mod prompt;
 pub mod progress;
 

apps/domain/src/lib.rs

@@ -57,6 +57,7 @@ pub use error::DomainError;
 // Agent module top-level items (TurnEvent, SessionRuntime, etc.)
 pub use agent::*;
 // Sub-module items need explicit re-exports
+pub use agent::defaults::*;
 pub use agent::progress::AgentProgress;
 pub use agent::prompt::{compaction_prompt, main_agent_prompt, subagent_directive};
 pub use workflow::*;

apps/domain/src/subagent/mod.rs

@@ -1,31 +1,5 @@
 //! Subagent domain models.
 
-/// Events emitted by a running subagent.
-#[derive(Debug, Clone)]
-pub enum SubagentEvent {
-    Started {
-        agent_id: String,
-        directive: String,
-    },
-    ToolCall {
-        agent_id: String,
-        tool_name: String,
-    },
-    ToolResult {
-        agent_id: String,
-        tool_name: String,
-        output: String,
-    },
-    Completed {
-        agent_id: String,
-        output: String,
-    },
-    Failed {
-        agent_id: String,
-        error: String,
-    },
-}
-
 /// Access tier for subagent tool permissions.
 ///
 /// Tiers are cumulative: `Write` includes everything in `Read`, and `Full`

apps/gateway/src/main.rs

@@ -144,15 +144,15 @@ fn run_api_server(port: u16) -> anyhow::Result<()> {
                 "JWT_SECRET environment variable not set; using insecure default. \
                  Set JWT_SECRET to a secure random value in production."
             );
-            "dev-secret".to_string()
+            zesdex_domain::agent::defaults::FALLBACK_JWT_SECRET.to_string()
         });
 
         let state = zesdex_api::ApiState::new(
             store.base_dir.clone(),
             jwt_secret,
             "",
-            "deepseek-v4-flash-free",
+            zesdex_domain::agent::defaults::DEFAULT_MODEL,
-            Some("https://opencode.ai/zen/v1".to_string()),
+            Some(zesdex_domain::agent::defaults::DEFAULT_API_BASE.to_string()),
         );
         let app = zesdex_api::build_router(state);
         let addr = std::net::SocketAddr::from(([0, 0, 0, 0], port));

apps/infrastructure/src/lib.rs

@@ -35,7 +35,6 @@ pub mod lsp;
 pub mod mcp;
 pub mod middleware;
 pub mod persistence;
-pub mod review;
 pub mod subagent;
 pub mod tools;
 pub mod utils;

apps/infrastructure/src/llm/provider.rs

@@ -11,8 +11,8 @@ use zesdex_domain::core::{
 };
 use zesdex_application::ports::ProviderService;
 
-const DEFAULT_BASE_URL: &str = "https://opencode.ai/zen/v1";
+use zesdex_domain::agent::defaults::{DEFAULT_API_BASE, DEFAULT_MODEL};
-const DEFAULT_MODEL: &str = "deepseek-v4-flash-free";
+const DEFAULT_BASE_URL: &str = DEFAULT_API_BASE;
 pub const DEFAULT_API_KEY: &str = "";
 const CONNECT_TIMEOUT: Duration = Duration::from_secs(10);
 const REQUEST_TIMEOUT: Duration = Duration::from_secs(600);

apps/infrastructure/src/review/mod.rs

@@ -1,8 +0,0 @@
-//! Post-edit auto-review subagent — validates file edits and suggests
-//! improvements.
-
-pub mod pending;
-pub mod probe;
-pub mod prompt;
-pub mod staleness;
-pub mod types;

apps/infrastructure/src/review/pending.rs

@@ -1,43 +0,0 @@
-//! Pending review queue — tracks files modified by tools that have not
-//! yet been reviewed.
-
-use std::collections::VecDeque;
-
-/// A file mutation awaiting review.
-#[derive(Debug, Clone)]
-pub struct PendingReview {
-    pub path: String,
-    pub tool: String,
-    pub reason: String,
-    pub content_sha256: String,
-}
-
-/// Queue of files modified but not yet reviewed.
-#[derive(Debug, Clone, Default)]
-pub struct PendingReviewQueue {
-    entries: VecDeque<PendingReview>,
-}
-
-impl PendingReviewQueue {
-    pub fn new() -> Self {
-        PendingReviewQueue {
-            entries: VecDeque::new(),
-        }
-    }
-
-    pub fn push(&mut self, entry: PendingReview) {
-        self.entries.push_back(entry);
-    }
-
-    pub fn pop(&mut self) -> Option<PendingReview> {
-        self.entries.pop_front()
-    }
-
-    pub fn is_empty(&self) -> bool {
-        self.entries.is_empty()
-    }
-
-    pub fn len(&self) -> usize {
-        self.entries.len()
-    }
-}

apps/infrastructure/src/review/probe.rs

@@ -1,18 +0,0 @@
-//! Review probe — diff analysis and file inspection for review purposes.
-
-use similar::{ChangeTag, TextDiff};
-
-/// Compute a simple unified diff between old and new text.
-pub fn compute_diff(old: &str, new: &str) -> String {
-    let diff = TextDiff::from_lines(old, new);
-    let mut result = String::new();
-    for change in diff.iter_all_changes() {
-        let sign = match change.tag() {
-            ChangeTag::Delete => "-",
-            ChangeTag::Insert => "+",
-            ChangeTag::Equal => " ",
-        };
-        result.push_str(&format!("{}{}", sign, change.value()));
-    }
-    result
-}

apps/infrastructure/src/review/prompt.rs

@@ -1,25 +0,0 @@
-//! Review prompt construction — builds the system prompt for the
-//! auto-review subagent.
-
-/// Build the review system prompt for the given diff and context.
-pub fn build_review_prompt(diff: &str, file_path: &str) -> String {
-    format!(
-        "You are a code reviewer. Review the following diff for file '{}':\n\
-         \n\
-         Focus on:\n\
-         1. Correctness — does the change introduce bugs?\n\
-         2. Security — does the change introduce vulnerabilities?\n\
-         3. Style — does the change follow best practices?\n\
-         4. Edge cases — are there unhandled edge cases?\n\
-         \n\
-         Diff:\n\
-         ```diff\n\
-         {}\n\
-         ```\n\
-         \n\
-         Provide your review as a JSON array of findings with \
-         'severity' (Info/Warning/Error), 'file', 'line' (optional), \
-         'message', and 'suggestion' (optional).",
-        file_path, diff
-    )
-}

apps/infrastructure/src/review/staleness.rs

@@ -1,15 +0,0 @@
-//! Staleness detection for lesson cache entries.
-
-use std::time::{SystemTime, UNIX_EPOCH};
-
-/// How long (in seconds) before a lesson is considered stale.
-const STALE_THRESHOLD_SECS: u64 = 86400 * 7; // 7 days
-
-/// Check whether a lesson timestamp is stale.
-pub fn is_stale(updated_at: i64) -> bool {
-    let now = SystemTime::now()
-        .duration_since(UNIX_EPOCH)
-        .unwrap_or_default()
-        .as_secs() as i64;
-    now.saturating_sub(updated_at) > STALE_THRESHOLD_SECS as i64
-}

apps/infrastructure/src/review/types.rs

@@ -1,29 +0,0 @@
-//! Review types — findings, severity, and configuration.
-
-use serde::{Deserialize, Serialize};
-
-/// Severity of a review finding.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
-pub enum ReviewSeverity {
-    Info,
-    Warning,
-    Error,
-}
-
-/// A single review finding from the auto-review subagent.
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct ReviewFinding {
-    pub severity: ReviewSeverity,
-    pub file: String,
-    pub line: Option<usize>,
-    pub message: String,
-    pub suggestion: Option<String>,
-}
-
-/// Configuration for the auto-review subagent.
-#[derive(Debug, Clone)]
-pub struct ReviewConfig {
-    pub max_lessons_per_run: usize,
-    pub adaptive_max_skip: u32,
-    pub enabled: bool,
-}

apps/infrastructure/src/subagent/auto/engine.rs

@@ -109,7 +109,7 @@ pub fn spawn_background_review(
         // 3. Resolve LLM credentials
         let base_url = api_base.unwrap_or_else(|| {
             std::env::var("OPENAI_API_BASE")
-                .unwrap_or_else(|_| "https://opencode.ai/zen/v1".to_string())
+                .unwrap_or_else(|_| zesdex_domain::agent::defaults::DEFAULT_API_BASE.to_string())
         });
 
         let client = LlmClient::new(api_key, model, Some(base_url));

apps/infrastructure/src/subagent/event.rs

@@ -1,3 +0,0 @@
-//! Subagent event types — events emitted during subagent execution.
-
-pub use zesdex_domain::subagent::SubagentEvent;

apps/infrastructure/src/subagent/gating.rs

@@ -1,23 +0,0 @@
-//! Subagent gating — decide whether to run review/test/arch agents based
-//! on the current context.
-
-use tracing::instrument;
-
-/// Determine whether an auto-review should be triggered after an edit.
-///
-/// Gating logic:
-/// - Returns `false` if there are no edits (`edit_count == 0`).
-/// - Returns `false` if `consecutive_empty_reviews >= max_skip` (too many
-///   consecutive reviews produced no findings, so skip further reviews).
-/// - Otherwise returns `true`.
-#[instrument]
-pub fn should_review(edit_count: u32, consecutive_empty_reviews: u32, max_skip: u32) -> bool {
-    if edit_count == 0 {
-        return false;
-    }
-    // Skip review if we've had several consecutive empty reviews
-    if consecutive_empty_reviews >= max_skip {
-        return false;
-    }
-    true
-}

apps/infrastructure/src/subagent/mod.rs

@@ -5,9 +5,5 @@ pub mod auto;
 pub mod context;
 pub mod division;
 pub mod engine;
-pub mod event;
-pub mod gating;
 pub mod provider;
 pub mod spawn;
-pub mod tools;
-pub mod workspace;

apps/infrastructure/src/subagent/provider.rs

@@ -67,7 +67,7 @@ impl SubagentProvider {
 ///
 /// Flow: reads `settings.provider` and `settings.model` → if model is empty,
 /// falls back to the provider config's `default_model` → if that is also
-/// empty, uses `"deepseek-v4-flash-free"` as the ultimate default.
+/// empty, uses the domain default model constant.
 #[instrument]
 pub fn resolve_subagent_provider(
     settings: &zesdex_domain::cms::Settings,
@@ -82,7 +82,7 @@ pub fn resolve_subagent_provider(
             .providers
             .get(&provider)
             .and_then(|p| p.default_model.clone())
-            .unwrap_or_else(|| "deepseek-v4-flash-free".to_string())
+            .unwrap_or_else(|| zesdex_domain::agent::defaults::DEFAULT_MODEL.to_string())
     } else {
         model
     };

apps/infrastructure/src/subagent/tools.rs

@@ -1,19 +0,0 @@
-//! Subagent tool helpers — wrap tool execution for subagent use.
-
-use anyhow::Result;
-use tracing::instrument;
-
-use crate::tools::{Tool, ToolCtx};
-
-/// Execute a single tool call within a subagent context.
-///
-/// Delegates directly to the tool's `run` method with the given context and
-/// JSON arguments.
-#[instrument(skip(tool, ctx, args))]
-pub fn execute_tool_call(
-    tool: &dyn Tool,
-    ctx: &ToolCtx,
-    args: &serde_json::Value,
-) -> Result<String> {
-    tool.run(ctx, args)
-}

apps/infrastructure/src/subagent/workspace.rs

@@ -1,16 +0,0 @@
-//! Subagent workspace management — create isolated workspaces for subagents.
-
-use std::path::{Path, PathBuf};
-
-use tracing::instrument;
-
-/// Create an isolated workspace directory for a subagent.
-///
-/// Creates `{base_dir}/subagent-workspaces/{agent_id}` and all parent
-/// directories if they do not already exist.
-#[instrument]
-pub fn create_subagent_workspace(base_dir: &Path, agent_id: &str) -> anyhow::Result<PathBuf> {
-    let ws = base_dir.join("subagent-workspaces").join(agent_id);
-    std::fs::create_dir_all(&ws)?;
-    Ok(ws)
-}

apps/infrastructure/src/tools/parallel_delegate.rs

@@ -100,7 +100,7 @@ impl Tool for ParallelDelegate {
             .providers
             .get(&provider)
             .map(|p| p.api_base.clone())
-            .unwrap_or_else(|| "https://opencode.ai/zen/v1".to_string());
+            .unwrap_or_else(|| zesdex_domain::agent::defaults::DEFAULT_API_BASE.to_string());
 
         let api_key = crate::llm::provider::resolve_api_key(&settings, &app_config);
 

apps/infrastructure/src/tools/plan.rs

@@ -45,8 +45,9 @@ impl Tool for PlanEnter {
         let plan_path = ctx.session_dir.join("PLAN.md");
         let _ = std::fs::write(&plan_path, &plan_text);
         if let Some(events) = &ctx.turn_events {
-            let mut q = events.lock().unwrap();
+            if let Ok(mut q) = events.lock() {
-            q.push_back(crate::TurnEvent::PlanUpdate(plan_text.clone()));
+                q.push_back(crate::TurnEvent::PlanUpdate(plan_text.clone()));
+            }
         }
 
         Ok(format!(
@@ -103,8 +104,9 @@ impl Tool for PlanReady {
             let plan_path = ctx.session_dir.join("PLAN.md");
             let _ = std::fs::write(&plan_path, &plan_content);
             if let Some(events) = &ctx.turn_events {
-                let mut q = events.lock().unwrap();
+                if let Ok(mut q) = events.lock() {
-                q.push_back(crate::TurnEvent::PlanUpdate(plan_content.clone()));
+                    q.push_back(crate::TurnEvent::PlanUpdate(plan_content.clone()));
+                }
             }
 
             Ok(format!("Plan saved to {filename}. Starting execution."))

apps/infrastructure/src/tools/spawn.rs

@@ -79,7 +79,7 @@ impl Tool for SpawnAgents {
             .providers
             .get(&provider)
             .map(|p| p.api_base.clone())
-            .unwrap_or_else(|| "https://opencode.ai/zen/v1".to_string());
+            .unwrap_or_else(|| zesdex_domain::agent::defaults::DEFAULT_API_BASE.to_string());
 
         let api_key = crate::llm::provider::resolve_api_key(&settings, &app_config);
 
@@ -196,7 +196,7 @@ impl Tool for SpawnPipeline {
             .providers
             .get(&provider)
             .map(|p| p.api_base.clone())
-            .unwrap_or_else(|| "https://opencode.ai/zen/v1".to_string());
+            .unwrap_or_else(|| zesdex_domain::agent::defaults::DEFAULT_API_BASE.to_string());
 
         let api_key = crate::llm::provider::resolve_api_key(&settings, &app_config);
 

apps/infrastructure/src/tools/utility/todofinish.rs

@@ -68,8 +68,9 @@ impl Tool for Todofinish {
             content = new_lines.join("\n") + "\n";
             let _ = std::fs::write(&todo_path, &content);
             if let Some(events) = &ctx.turn_events {
-                let mut q = events.lock().unwrap();
+                if let Ok(mut q) = events.lock() {
-                q.push_back(crate::TurnEvent::TodoUpdate(content));
+                    q.push_back(crate::TurnEvent::TodoUpdate(content));
+                }
             }
             info!(item, "TODO item completed and written back");
         } else {

apps/infrastructure/src/tools/utility/todowrite.rs

@@ -62,8 +62,9 @@ impl Tool for Todowrite {
         let _ = std::fs::write(&todo_path, &content);
 
         if let Some(events) = &ctx.turn_events {
-            let mut q = events.lock().unwrap();
+            if let Ok(mut q) = events.lock() {
-            q.push_back(crate::TurnEvent::TodoUpdate(content));
+                q.push_back(crate::TurnEvent::TodoUpdate(content));
+            }
         }
 
         info!(item, priority, "TODO item added");

apps/infrastructure/src/tools/workflow.rs

@@ -62,7 +62,7 @@ impl Tool for WorkflowRun {
 
         let llm_client = LlmClient::new(
             crate::llm::provider::DEFAULT_API_KEY.to_string(),
-            "deepseek-v4-flash-free".to_string(),
+            zesdex_domain::agent::defaults::DEFAULT_MODEL.to_string(),
             None,
         );
         let rt = tokio::runtime::Runtime::new()?;

apps/infrastructure/src/workflow/engine/primitives.rs

@@ -41,7 +41,7 @@ pub async fn execute_primitive(directive: &str, tool_ctx: &ToolCtx) -> Result<St
         .providers
         .get(&provider)
         .map(|p| p.api_base.clone())
-        .unwrap_or_else(|| "https://opencode.ai/zen/v1".to_string());
+        .unwrap_or_else(|| zesdex_domain::agent::defaults::DEFAULT_API_BASE.to_string());
 
     let api_key = crate::llm::provider::resolve_api_key(&settings, &app_config);
 

apps/infrastructure/src/workflow/hive_mind/cycle.rs

@@ -50,7 +50,7 @@ pub async fn execute_cycle(
         .providers
         .get(&provider)
         .map(|p| p.api_base.clone())
-        .unwrap_or_else(|| "https://opencode.ai/zen/v1".to_string());
+        .unwrap_or_else(|| zesdex_domain::agent::defaults::DEFAULT_API_BASE.to_string());
 
     let api_key = crate::llm::provider::resolve_api_key(&settings, &app_config);
 

apps/interfaces/daemon/src/server.rs

@@ -29,7 +29,8 @@ use crate::state::create_session;
 /// save settings, and release the lock.
 pub fn run_daemon() -> Result<()> {
     tracing::info!("starting daemon process");
-    let (store, _session_lock_guard, mut state, _rt) = create_session()?;
+    let (store, _session_lock_guard, mut state, rt) = create_session()?;
+    let _guard = rt.enter();
 
     let run_dir = store.base_dir.join("run");
     std::fs::create_dir_all(&run_dir)?;

apps/interfaces/tui/src/controller/input.rs

@@ -15,6 +15,7 @@ use crossterm::event::{KeyCode, KeyEvent, KeyModifiers};
 
 use crate::action::Action;
 use crate::controller::command::{apply_command, parse_command};
+use crate::controller::overlay_enter::handle_overlay_enter;
 use crate::state::{AutocompleteKind, Overlay, AppStateRest};
 
 /// Mark state dirty and return an empty action list.
@@ -329,112 +330,6 @@ pub fn handle_key(key: KeyEvent, state: &mut AppStateRest) -> Vec<Action> {
     }
 }
 
-/// Handle pressing Enter while a modal overlay is active.
-///
-/// Each overlay variant has its own Enter semantics:
-/// - `QuitConfirm` → set `quit = true`
-/// - `KeyInput` → save API key from buffer
-/// - `ModelSelector` → switch provider/model from selected index
-/// - `ClearConfirm` → clear transcript cache
-/// - `Rewind` → rewind to selected message index
-/// - `Bash` / `Settings` / `Todo` / `Mcp` → no-ops (placeholder)
-#[tracing::instrument(skip(state))]
-fn handle_overlay_enter(state: &mut AppStateRest) -> Vec<Action> {
-    debug!(overlay = ?state.misc.overlay, "handle_overlay_enter");
-    match state.misc.overlay {
-        Overlay::Bash => {
-            let command = state.input.buffer.clone();
-            state.toast_info(format!("Submitting bash command: {command}"));
-            state.input.buffer.clear();
-            state.input.cursor = 0;
-            state.mark_dirty();
-            Vec::new()
-        }
-        Overlay::Settings => {
-            state.mark_dirty();
-            Vec::new()
-        }
-        Overlay::Todo => {
-            state.mark_dirty();
-            Vec::new()
-        }
-        Overlay::QuitConfirm => {
-            state.quit = true;
-            state.mark_dirty();
-            Vec::new()
-        }
-        Overlay::KeyInput => {
-            let text = state.input.buffer.clone();
-            if !text.is_empty() {
-                state
-                    .settings
-                    .api_keys
-                    .insert(state.settings.provider.clone(), text);
-            }
-            state.toast_success("API key saved".to_string());
-            state.input.buffer.clear();
-            state.input.cursor = 0;
-            state.misc.overlay = Overlay::None;
-            state.save_settings();
-            state.mark_dirty();
-            Vec::new()
-        }
-        Overlay::Mcp => {
-            state.toast_info("Connecting MCP...".to_string());
-            Vec::new()
-        }
-        Overlay::Rewind => {
-            let idx = state.misc.selected_index;
-            let n = state.transcript_cache.messages.len();
-            if idx < n {
-                let rewind_to = n - idx - 1;
-                state.push_transcript(crate::state::ChatMessageDisplay::new(
-                    zesdex_domain::core::Role::System,
-                    format!("Rewound to message {rewind_to}"),
-                ));
-            }
-            state.misc.overlay = Overlay::None;
-            state.mark_dirty();
-            Vec::new()
-        }
-        Overlay::ModelSelector => {
-            let providers: Vec<String> = state.app_config.providers.keys().cloned().collect();
-            if let Some(provider) = providers.get(state.misc.selected_index) {
-                if let Some(cfg) = state.app_config.providers.get(provider) {
-                    let model = cfg.default_model.clone().unwrap_or_else(|| {
-                        "claude-opus-4-8".to_string()
-                    });
-                    state.settings.provider.clone_from(provider);
-                    state.settings.model.clone_from(&model);
-                    if let Some(ref key) = cfg.default_api_key {
-                        state.settings.api_keys.insert(provider.clone(), key.clone());
-                    } else if let Some(env_key) = cfg
-                        .api_key_env
-                        .as_ref()
-                        .and_then(|env| std::env::var(env).ok())
-                    {
-                        state.settings.api_keys.insert(provider.clone(), env_key);
-                    }
-                    state.save_settings();
-                    state.toast_success(format!("Switched to {provider} / {model}"));
-                }
-            }
-            state.misc.overlay = Overlay::None;
-            state.mark_dirty();
-            Vec::new()
-        }
-        Overlay::ClearConfirm => {
-            state.toast_info("Transcript cleared".to_string());
-            state.transcript_cache.messages.clear();
-            state.transcript_cache.dirty = true;
-            state.misc.overlay = Overlay::None;
-            state.mark_dirty();
-            Vec::new()
-        }
-        _ => Vec::new(),
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

apps/interfaces/tui/src/controller/mod.rs

@@ -9,3 +9,4 @@
 //!   commands into structured `Action` variants.
 pub mod command;
 pub mod input;
+pub mod overlay_enter;

apps/interfaces/tui/src/controller/overlay_enter.rs

@@ -0,0 +1,122 @@
+//! Overlay-specific Enter-key handlers.
+//!
+//! Each overlay variant has its own Enter semantics. Extracted from the
+//! monolithic `input.rs` so each handler is self-contained.
+
+use tracing::debug;
+
+use crate::action::Action;
+use crate::state::{AppStateRest, Overlay};
+
+/// Handle pressing Enter while a modal overlay is active.
+///
+/// Each overlay variant has its own Enter semantics:
+/// - `QuitConfirm` → set `quit = true`
+/// - `KeyInput` → save API key from buffer
+/// - `ModelSelector` → switch provider/model from selected index
+/// - `ClearConfirm` → clear transcript cache
+/// - `Rewind` → rewind to selected message index
+/// - `Bash` / `Settings` / `Todo` / `Mcp` → no-ops (placeholder)
+#[tracing::instrument(skip(state))]
+pub fn handle_overlay_enter(state: &mut AppStateRest) -> Vec<Action> {
+    debug!(overlay = ?state.misc.overlay, "handle_overlay_enter");
+    match state.misc.overlay {
+        Overlay::Bash => handle_bash_enter(state),
+        Overlay::Settings | Overlay::Todo => {
+            state.mark_dirty();
+            Vec::new()
+        }
+        Overlay::QuitConfirm => {
+            state.quit = true;
+            state.mark_dirty();
+            Vec::new()
+        }
+        Overlay::KeyInput => handle_keyinput_enter(state),
+        Overlay::Mcp => {
+            state.toast_info("Connecting MCP...".to_string());
+            Vec::new()
+        }
+        Overlay::Rewind => handle_rewind_enter(state),
+        Overlay::ModelSelector => handle_model_selector_enter(state),
+        Overlay::ClearConfirm => handle_clear_confirm(state),
+        _ => Vec::new(),
+    }
+}
+
+fn handle_bash_enter(state: &mut AppStateRest) -> Vec<Action> {
+    let command = state.input.buffer.clone();
+    state.toast_info(format!("Submitting bash command: {command}"));
+    state.input.buffer.clear();
+    state.input.cursor = 0;
+    state.mark_dirty();
+    Vec::new()
+}
+
+fn handle_keyinput_enter(state: &mut AppStateRest) -> Vec<Action> {
+    let text = state.input.buffer.clone();
+    if !text.is_empty() {
+        state
+            .settings
+            .api_keys
+            .insert(state.settings.provider.clone(), text);
+    }
+    state.toast_success("API key saved".to_string());
+    state.input.buffer.clear();
+    state.input.cursor = 0;
+    state.misc.overlay = Overlay::None;
+    state.save_settings();
+    state.mark_dirty();
+    Vec::new()
+}
+
+fn handle_rewind_enter(state: &mut AppStateRest) -> Vec<Action> {
+    let idx = state.misc.selected_index;
+    let n = state.transcript_cache.messages.len();
+    if idx < n {
+        let rewind_to = n - idx - 1;
+        state.push_transcript(crate::state::ChatMessageDisplay::new(
+            zesdex_domain::core::Role::System,
+            format!("Rewound to message {rewind_to}"),
+        ));
+    }
+    state.misc.overlay = Overlay::None;
+    state.mark_dirty();
+    Vec::new()
+}
+
+fn handle_model_selector_enter(state: &mut AppStateRest) -> Vec<Action> {
+    let providers: Vec<String> = state.app_config.providers.keys().cloned().collect();
+    if let Some(provider) = providers.get(state.misc.selected_index) {
+        if let Some(cfg) = state.app_config.providers.get(provider) {
+            let model = cfg
+                .default_model
+                .clone()
+                .unwrap_or_else(|| zesdex_domain::agent::defaults::DEFAULT_MODEL.to_string());
+            state.settings.provider.clone_from(provider);
+            state.settings.model.clone_from(&model);
+            if let Some(ref key) = cfg.default_api_key {
+                state.settings.api_keys.insert(provider.clone(), key.clone());
+            } else if let Some(env_key) = cfg
+                .api_key_env
+                .as_ref()
+                .and_then(|env| std::env::var(env).ok())
+            {
+                state.settings.api_keys.insert(provider.clone(), env_key);
+            }
+            state.save_settings();
+            state.toast_success(format!("Switched to {provider} / {model}"));
+        }
+    }
+    state.misc.overlay = Overlay::None;
+    state.mark_dirty();
+    Vec::new()
+}
+
+fn handle_clear_confirm(state: &mut AppStateRest) -> Vec<Action> {
+    state.toast_info("Transcript cleared".to_string());
+    state.transcript_cache.messages.clear();
+    state.transcript_cache.dirty = true;
+    state.misc.overlay = Overlay::None;
+    state.mark_dirty();
+    Vec::new()
+}

apps/interfaces/tui/src/run.rs

@@ -30,6 +30,9 @@ use crate::view;
 /// save settings.
 #[tracing::instrument]
 pub fn run_single_process() -> Result<()> {
+    let rt = tokio::runtime::Runtime::new()?;
+    let _guard = rt.enter();
+
     // Create session state
     info!("starting single-process TUI");
     let (_store, mut state) = create_local_session()?;

apps/interfaces/tui/src/turn.rs

@@ -130,3 +130,28 @@ pub fn spawn_agent_turn(state: &mut AppStateRest, text: String) {
         let _ = turn_service.run_turn(params).await;
     });
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_spawn_agent_turn_with_tokio_runtime() {
+        let rt = tokio::runtime::Runtime::new().unwrap();
+        let _guard = rt.enter();
+
+        let temp_dir = std::env::temp_dir().join(format!("zesdex_test_{}", uuid::Uuid::new_v4()));
+        let session_dir = temp_dir.join("session");
+        let memory_dir = temp_dir.join("memory");
+        std::fs::create_dir_all(&session_dir).unwrap();
+        std::fs::create_dir_all(&memory_dir).unwrap();
+
+        let workspace_roots = vec![temp_dir.clone()];
+        let mut state = AppStateRest::new(workspace_roots, &session_dir, memory_dir);
+
+        spawn_agent_turn(&mut state, "hello".to_string());
+        assert!(state.turn_in_flight());
+
+        let _ = std::fs::remove_dir_all(&temp_dir);
+    }
+}