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/supermemory/__init__.py

@@ -88,9 +88,9 @@ def _as_bool(value: Any, default: bool) -> bool:
         return value
     if isinstance(value, str):
         lowered = value.strip().lower()
-        if lowered in ("true", "1", "yes", "y", "on"):
+        if lowered in {"true", "1", "yes", "y", "on"}:
             return True
-        if lowered in ("false", "0", "no", "n", "off"):
+        if lowered in {"false", "0", "no", "n", "off"}:
             return False
     return default
 
@@ -508,7 +508,7 @@ class SupermemoryMemoryProvider(MemoryProvider):
         self._allowed_containers = [self._container_tag] + list(self._custom_containers)
 
         agent_context = kwargs.get("agent_context", "")
-        self._write_enabled = agent_context not in ("cron", "flush", "subagent")
+        self._write_enabled = agent_context not in {"cron", "flush", "subagent"}
         self._active = bool(self._api_key)
         self._client = None
         if self._active:
@@ -598,7 +598,7 @@ class SupermemoryMemoryProvider(MemoryProvider):
         cleaned = []
         for message in messages or []:
             role = message.get("role")
-            if role not in ("user", "assistant"):
+            if role not in {"user", "assistant"}:
                 continue
             content = _clean_text_for_capture(str(message.get("content", "")))
             if content: