workspace(refactor[builder]) route set-option loops through _bulk_set_options

why: Workspace loading dispatches one tmux ``set-option`` per
loop iteration across four hot loops (session ``options``,
``global_options``, per-window ``options``, ``options_after``).
The helper that ``f4c95faa`` introduced provides a single,
batch-shaped entry point for these calls; this commit moves the
existing call sites onto it. Today the helper is a plain loop
so this is a pure refactor (same N round-trips, same observable
behaviour). Once libtmux exposes a pipelined ``Server.batch()``
the helper body can swap internally and the call sites
automatically benefit without further changes here.

what:
- Replace the session ``options`` loop in ``build`` with
  ``_bulk_set_options(..., scope_flag="-s")`` targeting
  ``session.session_id``.
- Replace the ``global_options`` loop in ``build`` with
  ``_bulk_set_options(..., target=None, scope_flag="-g")``.
- Replace the per-window ``options`` loop in
  ``iter_create_windows`` with ``_bulk_set_options(...,
  scope_flag="-w")`` targeting ``window.window_id``.
- Replace the ``options_after`` loop in
  ``_apply_options_after`` (or equivalent post-build hook) with
  ``_bulk_set_options(..., scope_flag="-w")`` targeting
  ``window.window_id``.

Salvaged from libtmux-protocol@2390ce3b. The original commit
described the change as a perf win; against current libtmux
0.56.0 the helper body issues N round-trips per call site (no
``Server.batch()`` yet), so this commit is documented as a
refactor and the perf framing is deferred to whenever libtmux
ships a batching API.

Author: tony

src/tmuxp/workspace/builder.py

@@ -579,12 +579,18 @@ def build(self, session: Session | None = None, append: bool = False) -> None:
                     self.on_build_event({"event": "before_script_done"})
 
         if "options" in self.session_config:
-            for option, value in self.session_config["options"].items():
-                self.session.set_option(option, value)
+            self._bulk_set_options(
+                self.session_config["options"],
+                target=self.session.session_id,
+                scope_flag="-s",
+            )
 
         if "global_options" in self.session_config:
-            for option, value in self.session_config["global_options"].items():
-                self.session.set_option(option, value, global_=True)
+            self._bulk_set_options(
+                self.session_config["global_options"],
+                target=None,
+                scope_flag="-g",
+            )
 
         if "environment" in self.session_config:
             for option, value in self.session_config["environment"].items():
@@ -723,8 +729,11 @@ def iter_create_windows(
                 window_config["options"],
                 dict,
             ):
-                for key, val in window_config["options"].items():
-                    window.set_option(key, val)
+                self._bulk_set_options(
+                    window_config["options"],
+                    target=window.window_id,
+                    scope_flag="-w",
+                )
 
             if window_config.get("focus"):
                 window.select()
@@ -893,8 +902,11 @@ def config_after_window(
             window_config["options_after"],
             dict,
         ):
-            for key, val in window_config["options_after"].items():
-                window.set_option(key, val)
+            self._bulk_set_options(
+                window_config["options_after"],
+                target=window.window_id,
+                scope_flag="-w",
+            )
 
     def find_current_attached_session(self) -> Session:
         """Return current attached session."""