fix(policy): mypy narrowing for evaluator comparisons (homeassistant-ai#966)

`Predicate.value` is `Any | None` and `extract_path` returns `Any`, so
`val == pv`, `val > pv`, etc. inherit `Any` and trip the project's
`warn_return_any` mypy setting on functions declared `-> bool`. Wrap
the comparison branches in `bool(...)` to make the narrowing explicit.

Also guard the `regex` branch with `isinstance(pv, str)` so `re.search`
receives a definite `str` instead of `Any | None`; a non-string regex
value now returns False instead of raising TypeError at evaluation
time, which is the only sensible behavior for a malformed pattern.

No change to any test's expected outcome.

Author: kingpanther13

src/ha_mcp/policy/evaluator.py

@@ -40,22 +40,26 @@ def match_predicate(predicate: Predicate, args: dict[str, Any]) -> bool:
     pv = predicate.value
     match predicate.op:
         case "eq":
-            return val == pv
+            return bool(val == pv)
         case "neq":
-            return val != pv
+            return bool(val != pv)
         case "in":
             return val in (pv or [])
         case "not_in":
             return val not in (pv or [])
         # `regex` is re.search (substring match). Anchor with ^...$ for full-match.
         case "regex":
-            return isinstance(val, str) and re.search(pv, val) is not None
+            return (
+                isinstance(val, str)
+                and isinstance(pv, str)
+                and re.search(pv, val) is not None
+            )
         case "contains":
             return isinstance(val, (str, list, tuple, set)) and pv in val
         case "gt":
-            return val > pv
+            return bool(val > pv)
         case "lt":
-            return val < pv
+            return bool(val < pv)
     return False