feat: add provider-neutral tracker automation

tracker/errors.py

@@ -0,0 +1,21 @@
+class TrackerError(Exception):
+    """A stable, user-facing tracker failure."""
+
+    def __init__(self, code, message, *, retryable=False, provider=None, operation=None, details=None):
+        super().__init__(message)
+        self.code = code
+        self.message = message
+        self.retryable = retryable
+        self.provider = provider
+        self.operation = operation
+        self.details = details or {}
+
+    def to_dict(self):
+        return {
+            "code": self.code,
+            "message": self.message,
+            "retryable": self.retryable,
+            "provider": self.provider,
+            "operation": self.operation,
+            "details": self.details,
+        }