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/teams_pipeline/cli.py

@@ -99,15 +99,15 @@ def teams_pipeline_command(args: argparse.Namespace) -> int:
         return 2
 
     try:
-        if action in ("list", "ls"):
+        if action in {"list", "ls"}:
             _cmd_list(args)
         elif action == "show":
             _cmd_show(args)
-        elif action in ("run", "replay"):
+        elif action in {"run", "replay"}:
             _cmd_run(args)
-        elif action in ("fetch", "test"):
+        elif action in {"fetch", "test"}:
             _cmd_fetch(args)
-        elif action in ("subscriptions", "subs"):
+        elif action in {"subscriptions", "subs"}:
             _cmd_subscriptions(args)
         elif action == "subscribe":
             _cmd_subscribe(args)
@@ -117,7 +117,7 @@ def teams_pipeline_command(args: argparse.Namespace) -> int:
             _cmd_delete_subscription(args)
         elif action == "maintain-subscriptions":
             _cmd_maintain_subscriptions(args)
-        elif action in ("token-health", "token"):
+        elif action in {"token-health", "token"}:
             _cmd_token_health(args)
         elif action == "validate":
             _cmd_validate(args)