fix: improve milestone name resolution and project scoping

- Enhance resolve_milestone_id() with project-aware search priority
- Add project context prioritization in milestone resolution
- Improve fallback behavior for cross-project milestone search

This ensures milestone lookup by name works reliably by first searching
within the specified project context, then falling back to global search.
Resolves failed lookups when multiple milestones have the same name
across different projects.

Author: AdiKsOnDev

src/linear_cli/api/client/client.py

@@ -1273,12 +1273,22 @@ async def resolve_milestone_id(
         ):
             return milestone_identifier
 
-        # Search for milestone by name  
-        # NOTE: Temporarily searching all milestones due to GraphQL filter issues
-        # TODO: Fix project-scoped milestone filtering
+        # Search for milestone by name
+        # WHY: Linear's GraphQL doesn't support direct project filtering for milestones
+        # so we fetch all milestones and filter client-side with project preference
         milestones_data = await self.get_milestones(limit=100)
 
         nodes = milestones_data.get("nodes", [])
+        
+        # If project_id provided, prioritize milestones from that project
+        if project_id:
+            # First pass: look for exact match in the specified project
+            for milestone in nodes:
+                if (milestone.get("name", "").lower() == milestone_identifier.lower() and
+                    milestone.get("project", {}).get("id") == project_id):
+                    return milestone.get("id")
+        
+        # Fallback: search all milestones without project constraint
         for milestone in nodes:
             if milestone.get("name", "").lower() == milestone_identifier.lower():
                 return milestone.get("id")