chore: ruff auto-fix PLR6201 — tuple → set in membership tests (#23937)

Replace  with  for all literal-tuple
membership tests. Set lookup is O(1) vs O(n) for tuple — consistent
micro-optimization across the codebase.

608 instances fixed via `ruff --fix --unsafe-fixes`, 0 remaining.
133 files, +626/-626 (net zero).

agent/memory_manager.py

@@ -470,11 +470,11 @@ class MemoryManager:
 
         accepted = [
             p for p in params
-            if p.kind in (
+            if p.kind in {
                 inspect.Parameter.POSITIONAL_ONLY,
                 inspect.Parameter.POSITIONAL_OR_KEYWORD,
                 inspect.Parameter.KEYWORD_ONLY,
-            )
+            }
         ]
         if len(accepted) >= 4:
             return "positional"