refactor: use impl Effect return types and stillwater helpers

Update Effect-based functions to use impl Trait return syntax and
Stillwater's standalone helper functions (asks, local, from_async)
instead of Effect:: associated functions. This aligns with idiomatic
Rust and the updated Stillwater API.

Changes across mapreduce effects, environment helpers, orchestrator,
workflow effects, and unified session modules.

Author: iepathos

Cargo.lock

@@ -56,9 +56,9 @@ hostname = "0.4"
 nix = { version = "0.30", features = ["signal", "process"] }
 sysinfo = "0.37.1"
 dirs = "6.0.0"
-stillwater = "0.8.0"
+stillwater = "0.11.0"
 rayon = "1.11.0"
-premortem = { version = "0.3.0", features = ["toml", "yaml", "derive"] }
+premortem = { path = "../premortem", features = ["toml", "yaml", "derive"] }
 
 [features]
 default = []

Cargo.toml

@@ -11,7 +11,7 @@ use crate::cook::execution::mapreduce::effects::worktree::Worktree;
 use crate::cook::execution::mapreduce::environment::MapEnv;
 use serde_json::Value;
 use std::collections::HashMap;
-use stillwater::Effect;
+use stillwater::{from_async, Effect};
 
 /// Result from command execution
 #[derive(Debug, Clone)]
@@ -44,11 +44,11 @@ pub struct CommandResult {
 pub fn execute_commands_effect(
     item: &Value,
     worktree: &Worktree,
-) -> Effect<CommandResult, MapReduceError, MapEnv> {
+) -> impl Effect<Output = CommandResult, Error = MapReduceError, Env = MapEnv> {
     let item = item.clone();
     let worktree = worktree.clone();
 
-    Effect::from_async(move |env: &MapEnv| {
+    from_async(move |env: &MapEnv| {
         let item = item.clone();
         let worktree = worktree.clone();
         let _command_executor = env.command_executor.clone();

src/cook/execution/mapreduce/effects/commands.rs

@@ -9,7 +9,7 @@
 use crate::cook::execution::errors::MapReduceError;
 use crate::cook::execution::mapreduce::effects::worktree::Worktree;
 use crate::cook::execution::mapreduce::environment::MapEnv;
-use stillwater::Effect;
+use stillwater::{from_async, Effect};
 
 /// Result from merge operation
 #[derive(Debug, Clone)]
@@ -39,10 +39,10 @@ pub struct MergeResult {
 pub fn merge_to_parent_effect(
     worktree: &Worktree,
     _parent_branch: &str,
-) -> Effect<MergeResult, MapReduceError, MapEnv> {
+) -> impl Effect<Output = MergeResult, Error = MapReduceError, Env = MapEnv> {
     let _worktree_name = worktree.name.clone();
 
-    Effect::from_async(move |env: &MapEnv| {
+    from_async(move |env: &MapEnv| {
         let _worktree_manager = env.worktree_manager.clone();
 
         async move {
@@ -62,8 +62,10 @@ pub fn merge_to_parent_effect(
 ///
 /// Checks whether an agent's worktree has any commits that need to be merged.
 /// Used for commit validation and optimization.
-pub fn has_commits_effect(_worktree: &Worktree) -> Effect<bool, MapReduceError, MapEnv> {
-    Effect::from_async(move |env: &MapEnv| {
+pub fn has_commits_effect(
+    _worktree: &Worktree,
+) -> impl Effect<Output = bool, Error = MapReduceError, Env = MapEnv> {
+    from_async(move |env: &MapEnv| {
         let _worktree_manager = env.worktree_manager.clone();
 
         async move {
@@ -76,8 +78,10 @@ pub fn has_commits_effect(_worktree: &Worktree) -> Effect<bool, MapReduceError,
 /// Effect: Get list of commits in worktree
 ///
 /// Retrieves the list of commits made in an agent's worktree.
-pub fn list_commits_effect(_worktree: &Worktree) -> Effect<Vec<String>, MapReduceError, MapEnv> {
-    Effect::from_async(move |env: &MapEnv| {
+pub fn list_commits_effect(
+    _worktree: &Worktree,
+) -> impl Effect<Output = Vec<String>, Error = MapReduceError, Env = MapEnv> {
+    from_async(move |env: &MapEnv| {
         let _worktree_manager = env.worktree_manager.clone();
 
         async move {

src/cook/execution/mapreduce/effects/merge.rs

@@ -6,7 +6,7 @@
 use crate::cook::execution::errors::MapReduceError;
 use crate::cook::execution::mapreduce::environment::MapEnv;
 use std::path::PathBuf;
-use stillwater::Effect;
+use stillwater::{from_async, Effect};
 
 /// Worktree information
 #[derive(Debug, Clone)]
@@ -36,10 +36,10 @@ pub struct Worktree {
 pub fn create_worktree_effect(
     name: &str,
     _parent_branch: &str,
-) -> Effect<Worktree, MapReduceError, MapEnv> {
+) -> impl Effect<Output = Worktree, Error = MapReduceError, Env = MapEnv> {
     let name = name.to_string();
 
-    Effect::from_async(move |env: &MapEnv| {
+    from_async(move |env: &MapEnv| {
         let name = name.clone();
         let _worktree_manager = env.worktree_manager.clone();
 
@@ -70,8 +70,10 @@ pub fn create_worktree_effect(
 /// let effect = remove_worktree_effect(&worktree);
 /// effect.run_async(&env).await?;
 /// ```
-pub fn remove_worktree_effect(_worktree: &Worktree) -> Effect<(), MapReduceError, MapEnv> {
-    Effect::from_async(move |env: &MapEnv| {
+pub fn remove_worktree_effect(
+    _worktree: &Worktree,
+) -> impl Effect<Output = (), Error = MapReduceError, Env = MapEnv> {
+    from_async(move |env: &MapEnv| {
         let _worktree_manager = env.worktree_manager.clone();
 
         async move {