stt: omit model field when empty (fixes Riva 400); settings: always-visible scrollbar (v2.0.3)

- stt._transcribe_remote: no longer falls back to "whisper-1" when
  engine.model is empty — omits the field entirely so Riva/NIM uses its
  default model instead of rejecting the request with HTTP 400
- gtksettings._page: switch vertical scroll policy to ALWAYS and disable
  overlay scrolling so the scrollbar is permanently visible, making
  it obvious when a tab has more content below the visible area

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

linux/blitztext/__init__.py

@@ -6,4 +6,4 @@ counterpart to the macOS Blitztext menu bar app: it runs natively on the host
 (not in a container) so it can type into any application via xdotool.
 """
 
-__version__ = "2.0.2"
+__version__ = "2.0.3"

linux/blitztext/gtksettings.py

@@ -505,7 +505,8 @@ def _page(nb: Gtk.Notebook, title: str) -> Gtk.Box:
     outer = Gtk.Box(orientation=Gtk.Orientation.VERTICAL)
     nb.append_page(outer, Gtk.Label(label=title))
     sw = Gtk.ScrolledWindow()
-    sw.set_policy(Gtk.PolicyType.NEVER, Gtk.PolicyType.AUTOMATIC)
+    sw.set_policy(Gtk.PolicyType.NEVER, Gtk.PolicyType.ALWAYS)
+    sw.set_overlay_scrolling(False)  # always-visible scrollbar, not the overlay kind
     outer.pack_start(sw, True, True, 0)
     inner = Gtk.Box(orientation=Gtk.Orientation.VERTICAL, spacing=2)
     for m in ("top", "bottom", "start", "end"):

linux/blitztext/stt.py

@@ -138,7 +138,9 @@ def _transcribe_remote(engine: STTEngine, audio_path: Path, *, language: str, pr
 
     base = engine.url.rstrip("/")
     endpoint = base + "/audio/transcriptions"
-    fields = {"model": engine.model or "whisper-1", "response_format": "json"}
+    fields: dict[str, str] = {"response_format": "json"}
+    if engine.model:
+        fields["model"] = engine.model
     if language:
         fields["language"] = language
     if prompt: