Added star catalog search API

csst_fs/star_catalog/search.py

+import os
+import requests
+from typing import Dict, Any, List
+
+def query_star_catalog(
+    catalog_name: str,
+    filter: Dict[str, Any],
+    key: List[str],
+) -> List[Dict[str, Any]]:
+    """
+    Query a star catalog by column values given a ra, dec and radius preselection.
+
+    Args:
+        catalog_name: Name of the star catalog (e.g. msc_l1_mbi_catmix)
+        filter: The filter dict described below.
+            The following keys MUST be set:
+            {
+                "ra": 40.3,
+                "dec": 21.9,
+                "radius": 0.2,
+            }
+            Setting ranges with (lt, gt, lte, gte) for ra, dec values is not supported.
+        key: A list of string values, corresponding to the column names that should be present in the return value.
+
+    Returns:
+        A List[Dict] of matching star catalog objects.
+    """
+
+    for required_key in ("ra", "dec", "radius"):
+        if required_key not in filter or isinstance(filter[required_key], dict):
+            raise ValueError(f"Filter must contain scalar '{required_key}'")
+
+    if not key:
+        raise ValueError("Key list cannot be empty")
+
+    api_url = os.getenv("STAR_CATALOG_SEARCH_API_URL")
+    if not api_url:
+        raise RuntimeError("STAR_CATALOG_SEARCH_API_URL environment variable is not set")
+
+    endpoint = f"{api_url}/starcatalog/query"
+
+    payload = {
+        "catalogName": catalog_name,
+        "filter": filter,
+        "key": key,
+    }
+
+    try:
+        response = requests.post(endpoint, json=payload, timeout=30)
+        response.raise_for_status()
+    except requests.RequestException as e:
+        raise RuntimeError(f"Star catalog query failed: {e}")
+
+    data = response.json()
+
+    if not data.get("success") or "result" not in data:
+        raise RuntimeError(f"Unexpected API response: {data}")
+
+    return data["result"]