init+contexte : am init genere un agent-manager.yaml selon la stack detectee + contexte projet (git root, branche, stack) attache aux evenements et sessions (issue #8)

src/events.rs

@@ -113,8 +113,8 @@ impl Event {
         self
     }
 
-    pub fn with_project(mut self, project: impl Into<String>) -> Self {
-        self.project = Some(project.into());
+    pub fn with_project(mut self, project: Option<String>) -> Self {
+        self.project = project;
         self
     }