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)).

agent/lsp/client.py

@@ -232,7 +232,7 @@ class LSPClient:
         the process is killed and the client is left in state
         ``"error"`` — re-call ``start()`` to retry.
         """
-        if self._state in ("running", "starting"):
+        if self._state in {"running", "starting"}:
             return
         self._state = "starting"
         try:

agent/lsp/install.py

@@ -151,7 +151,7 @@ def try_install(pkg: str, strategy: str = "auto") -> Optional[str]:
     same path (or ``None``) without reinstalling.  Concurrent calls
     are serialized.
     """
-    if strategy not in ("auto",):
+    if strategy not in {"auto",}:
         # Only ``auto`` triggers an actual install.  In manual/off,
         # we still check whether the binary already exists.
         recipe = INSTALL_RECIPES.get(pkg, {})

agent/lsp/manager.py

@@ -162,7 +162,7 @@ class LSPService:
         idle_timeout: float = DEFAULT_IDLE_TIMEOUT,
     ) -> None:
         self._enabled = enabled
-        self._wait_mode = wait_mode if wait_mode in ("document", "full") else "document"
+        self._wait_mode = wait_mode if wait_mode in {"document", "full"} else "document"
         self._wait_timeout = wait_timeout
         self._install_strategy = install_strategy
         self._binary_overrides = binary_overrides or {}

agent/lsp/reporter.py

@@ -28,7 +28,7 @@ def format_diagnostic(d: Dict[str, Any]) -> str:
     col = int(start.get("character", 0)) + 1
     msg = str(d.get("message") or "").rstrip()
     code = d.get("code")
-    code_part = f" [{code}]" if code not in (None, "") else ""
+    code_part = f" [{code}]" if code not in {None, ""} else ""
     source = d.get("source")
     source_part = f" ({source})" if source else ""
     return f"{sev} [{line}:{col}] {msg}{code_part}{source_part}"

agent/lsp/servers.py

@@ -237,7 +237,7 @@ def _spawn_pyright(root: str, ctx: ServerContext) -> Optional[SpawnSpec]:
             return None
     # If we got the cli ``pyright``, the langserver is its sibling.
     base = os.path.basename(bin_path)
-    if base in ("pyright", "pyright.exe"):
+    if base in {"pyright", "pyright.exe"}:
         sibling = os.path.join(os.path.dirname(bin_path), "pyright-langserver")
         if os.path.exists(sibling):
             bin_path = sibling

agent/transports/codex_app_server_session.py

@@ -541,7 +541,7 @@ class CodexAppServerSession:
                 turn_status = (
                     (note.get("params") or {}).get("turn") or {}
                 ).get("status")
-                if turn_status and turn_status not in ("completed", "interrupted"):
+                if turn_status and turn_status not in {"completed", "interrupted"}:
                     err_obj = (
                         (note.get("params") or {}).get("turn") or {}
                     ).get("error")
@@ -775,9 +775,9 @@ def _approval_choice_to_codex_decision(choice: str) -> str:
     (verified against codex-rs/app-server-protocol/src/protocol/v2/item.rs
     on codex 0.130.0).
     """
-    if choice in ("once",):
+    if choice in {"once",}:
         return "accept"
-    if choice in ("session", "always"):
+    if choice in {"session", "always"}:
         return "acceptForSession"
     return "decline"