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/honcho/__init__.py

@@ -283,7 +283,7 @@ class HonchoMemoryProvider(MemoryProvider):
             # ----- Port #4053: cron guard -----
             agent_context = kwargs.get("agent_context", "")
             platform = kwargs.get("platform", "cli")
-            if agent_context in ("cron", "flush") or platform == "cron":
+            if agent_context in {"cron", "flush"} or platform == "cron":
                 logger.debug("Honcho skipped: cron/flush context (agent_context=%s, platform=%s)",
                              agent_context, platform)
                 self._cron_skipped = True
@@ -404,7 +404,7 @@ class HonchoMemoryProvider(MemoryProvider):
         # pop_context_result() in prefetch(). Dialectic prewarm runs the
         # full configured depth and writes into _prefetch_result so turn 1
         # consumes the result directly.
-        if self._recall_mode in ("context", "hybrid"):
+        if self._recall_mode in {"context", "hybrid"}:
             try:
                 self._manager.prefetch_context(self._session_key)
             except Exception as e: