fix(utils): coerce Tavily usage counters to int

JSON APIs sometimes return numeric fields as strings; subtracting them raised TypeError and /status dropped the usage block.

nanobot/utils/searchusage.py

@@ -146,8 +146,8 @@ def _parse_tavily_usage(data: dict[str, Any]) -> SearchUsageInfo:
     }
     """
     account = data.get("account") or {}
-    used = account.get("plan_usage")
-    limit = account.get("plan_limit")
+    used = _optional_int(account.get("plan_usage"))
+    limit = _optional_int(account.get("plan_limit"))
 
     # Compute remaining
     remaining = None
@@ -160,9 +160,19 @@ def _parse_tavily_usage(data: dict[str, Any]) -> SearchUsageInfo:
         used=used,
         limit=limit,
         remaining=remaining,
-        search_used=account.get("search_usage"),
-        extract_used=account.get("extract_usage"),
-        crawl_used=account.get("crawl_usage"),
+        search_used=_optional_int(account.get("search_usage")),
+        extract_used=_optional_int(account.get("extract_usage")),
+        crawl_used=_optional_int(account.get("crawl_usage")),
     )
 
 
+def _optional_int(value: Any) -> int | None:
+    """Coerce JSON numerics (including string forms) to int; else None."""
+    if value is None:
+        return None
+    try:
+        return int(value)
+    except (TypeError, ValueError):
+        return None
+
+

tests/utils/test_searchusage.py

@@ -126,6 +126,24 @@ class TestParseTavilyUsage:
         assert info.extract_used is None
         assert info.crawl_used is None
 
+    def test_string_numeric_fields(self):
+        data = {
+            "account": {
+                "plan_usage": "10",
+                "plan_limit": "100",
+                "search_usage": "7",
+                "extract_usage": "2",
+                "crawl_usage": "1",
+            },
+        }
+        info = _parse_tavily_usage(data)
+        assert info.used == 10
+        assert info.limit == 100
+        assert info.remaining == 90
+        assert info.search_used == 7
+        assert info.extract_used == 2
+        assert info.crawl_used == 1
+
 
 # ---------------------------------------------------------------------------
 # fetch_search_usage routing tests