feat(server): refactor handlers, router, state management, and memory tools

server/src/models.rs

@@ -219,3 +219,18 @@ pub struct TerminalHistory {
     pub timestamp: u64,
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+pub struct ActivityRecord {
+    pub timestamp: u64,
+    pub category: String, // e.g. "code_change", "task_update", "telemetry", "error_fix"
+    pub summary: String,  // Brief human-readable description of what is being worked on
+    pub details: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+pub struct StateSnapshot {
+    pub id: String,
+    pub timestamp: u64,
+    pub description: String,
+    pub namespace: String,
+}