feat: implement worktree session creation and management

- Added `createWorktreeSession` utility to handle the creation of new sessions with auto-generated worktrees.
- Introduced branch name generation utilities for creating unique and friendly branch names.
- Updated `CommandPalette` to trigger worktree session creation via a command.
- Refactored keyboard shortcuts to support new worktree session creation with Shift + Cmd/Ctrl + N.
- Enhanced project settings to include worktree defaults (branch prefix, base branch, auto-create option).
- Updated persistence logic to preserve worktree defaults when saving project settings.
- Modified menu actions to initiate new worktree sessions.
- Ensured proper handling of existing branches to avoid conflicts during worktree creation.

packages/desktop/src-tauri/src/commands/settings.rs

@@ -135,6 +135,27 @@ fn sanitize_projects(value: &Value) -> Option<Value> {
             }
         }
 
+        // Preserve worktreeDefaults
+        if let Some(Value::Object(wt)) = obj.get("worktreeDefaults") {
+            let mut defaults = serde_json::Map::new();
+            if let Some(Value::String(s)) = wt.get("branchPrefix") {
+                if !s.trim().is_empty() {
+                    defaults.insert("branchPrefix".to_string(), json!(s.trim()));
+                }
+            }
+            if let Some(Value::String(s)) = wt.get("baseBranch") {
+                if !s.trim().is_empty() {
+                    defaults.insert("baseBranch".to_string(), json!(s.trim()));
+                }
+            }
+            if let Some(Value::Bool(b)) = wt.get("autoCreateWorktree") {
+                defaults.insert("autoCreateWorktree".to_string(), json!(b));
+            }
+            if !defaults.is_empty() {
+                project.insert("worktreeDefaults".to_string(), Value::Object(defaults));
+            }
+        }
+
         result.push(Value::Object(project));
     }