feat(mma): Implement TrackDAG for dependency resolution and cycle detection

dag_engine.py

@@ -0,0 +1,52 @@
+from typing import List
+from models import Ticket
+
+class TrackDAG:
+    def __init__(self, tickets: List[Ticket]):
+        self.tickets = tickets
+        self.ticket_map = {t.id: t for t in tickets}
+
+    def get_ready_tasks(self) -> List[Ticket]:
+        """Returns tickets that are 'todo' and whose dependencies are all 'completed'."""
+        ready = []
+        for ticket in self.tickets:
+            if ticket.status == 'todo':
+                # Check if all dependencies exist and are completed
+                all_done = True
+                for dep_id in ticket.depends_on:
+                    dep = self.ticket_map.get(dep_id)
+                    if not dep or dep.status != 'completed':
+                        all_done = False
+                        break
+                if all_done:
+                    ready.append(ticket)
+        return ready
+
+    def has_cycle(self) -> bool:
+        """Returns True if there's a dependency cycle."""
+        visited = set()
+        rec_stack = set()
+
+        def is_cyclic(ticket_id):
+            if ticket_id in rec_stack:
+                return True
+            if ticket_id in visited:
+                return False
+
+            visited.add(ticket_id)
+            rec_stack.add(ticket_id)
+
+            ticket = self.ticket_map.get(ticket_id)
+            if ticket:
+                for neighbor in ticket.depends_on:
+                    if is_cyclic(neighbor):
+                        return True
+
+            rec_stack.remove(ticket_id)
+            return False
+
+        for ticket in self.tickets:
+            if ticket.id not in visited:
+                if is_cyclic(ticket.id):
+                    return True
+        return False