chore: ruff auto-fix PLR6201 resweep — tuple → set in membership tests (#27355)

Six days after #23937 (608 fixes) the codebase had accumulated 241 new
PLR6201 violations. Same mechanical `x in (...)` → `x in {...}` fix,
same zero-risk profile: set lookup is O(1) vs O(n) for tuple and the
two are semantically equivalent for hashable scalar membership tests.

All 241 instances fixed via `ruff check --select PLR6201 --fix
--unsafe-fixes`, zero remaining. Every changed value is a hashable
scalar (str/int/None/enum/signal); no risk of unhashable runtime
errors. No behavior change.

Test plan:
- 119 files changed, +244/-244 (net zero) — exactly one-line edits
- `ruff check` clean afterward
- Compile checks pass on the largest touched files (cli.py, run_agent.py,
  gateway/run.py, gateway/platforms/discord.py, model_tools.py)
- Subset broad test run on tests/gateway/ tests/hermes_cli/ tests/agent/
  tests/tools/: 18187 passed, 59 pre-existing failures (verified against
  origin/main with the same shape — identical failure count, identical
  category — all xdist test-order flakes unrelated to this change)

Follows the same template as PR #23937 ([tracker: #23972](https://github.com/NousResearch/hermes-agent/issues/23972)).

plugins/memory/openviking/__init__.py

@@ -357,7 +357,7 @@ def _is_windows_absolute_path(value: str) -> bool:
         len(value) >= 3
         and value[0].isalpha()
         and value[1] == ":"
-        and value[2] in ("/", "\\")
+        and value[2] in {"/", "\\"}
     )
 
 
@@ -381,7 +381,7 @@ def _is_local_path_reference(value: str) -> bool:
 
 def _path_from_file_uri(uri: str) -> Path | str:
     parsed = urlparse(uri)
-    if parsed.netloc not in ("", "localhost"):
+    if parsed.netloc not in {"", "localhost"}:
         return f"Unsupported non-local file URI: {uri}"
     return Path(url2pathname(parsed.path)).expanduser()
 
@@ -755,7 +755,7 @@ class OpenVikingMemoryProvider(MemoryProvider):
 
         level = args.get("level", "overview")
 
-        summary_level = level in ("abstract", "overview")
+        summary_level = level in {"abstract", "overview"}
         # OpenViking expects directory URIs for pseudo summary files
         # (e.g. viking://user/hermes/.overview.md).
         resolved_uri = self._normalize_summary_uri(uri) if summary_level else uri
@@ -832,7 +832,7 @@ class OpenVikingMemoryProvider(MemoryProvider):
         result = self._unwrap_result(resp)
 
         # Format list/tree results for readability
-        if action in ("list", "tree"):
+        if action in {"list", "tree"}:
             raw_entries = result
             if isinstance(result, dict):
                 raw_entries = result.get("entries") or result.get("items") or result.get("children") or []
@@ -887,7 +887,7 @@ class OpenVikingMemoryProvider(MemoryProvider):
 
         payload: Dict[str, Any] = {}
         for key in ("reason", "to", "parent", "instruction", "wait", "timeout"):
-            if key in args and args[key] not in (None, ""):
+            if key in args and args[key] not in {None, ""}:
                 payload[key] = args[key]
 
         parsed_url = urlparse(url)