feat: Save buttons in header bar, remove Close button, center section icons (v2.03.13)

HeaderBar replaces bottom button row — Save and Save & Restart appear in the
title bar on the right, X button closes. Section header icons vertically
centered using SMALL_TOOLBAR size and valign=CENTER.

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

linux/CHANGELOG.md

@@ -9,6 +9,15 @@ The version is defined in [`blitztext/__init__.py`](blitztext/__init__.py).
 
 ## [Unreleased]
 
+## [2.03.13] - 2026-06-10
+
+### Changed
+- **Settings header bar.** Save and Save & Restart moved from the bottom button
+  bar into the title bar (GTK HeaderBar). The X button closes without saving.
+  Bottom button row removed.
+- **Section icon alignment.** Icons in section headers are now vertically
+  centred with the label text (`SMALL_TOOLBAR` size, `valign=CENTER`).
+
 ## [2.03.12] - 2026-06-10
 
 ### Added

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__ = "2.03.12"
+__version__ = "2.03.13"

linux/blitztext/gtksettings.py

@@ -307,12 +307,15 @@ def _section_title(parent: Gtk.Box, text: str, margin_top: int = 16,
     """A small bold uppercase section header, with optional symbolic icon."""
     row = Gtk.Box(spacing=5)
     row.set_margin_top(margin_top); row.set_margin_bottom(3)
+    row.set_valign(Gtk.Align.CENTER)
     row.get_style_context().add_class("bt-section")
     if icon:
-        img = Gtk.Image.new_from_icon_name(icon, Gtk.IconSize.MENU)
+        img = Gtk.Image.new_from_icon_name(icon, Gtk.IconSize.SMALL_TOOLBAR)
+        img.set_valign(Gtk.Align.CENTER)
         img.get_style_context().add_class("bt-section")
         row.pack_start(img, False, False, 0)
     lbl = Gtk.Label(xalign=0.0)
+    lbl.set_valign(Gtk.Align.CENTER)
     lbl.set_markup(f"<b><small>{GLib.markup_escape_text(text.upper())}</small></b>")
     row.pack_start(lbl, False, False, 0)
     parent.pack_start(row, False, False, 0)
@@ -735,11 +738,21 @@ class SettingsDialog:
         self._tr_cache: dict = {}
         self._wf_idx = self._stt_idx = self._llm_idx = 0
 
-        self.dlg = Gtk.Dialog(title="Blitztext — Settings", transient_for=parent, modal=True)
+        self.dlg = Gtk.Dialog(transient_for=parent, modal=True)
         self.dlg.set_default_size(740, 700)
-        self.dlg.add_button("Close", Gtk.ResponseType.CLOSE)
+
-        self.dlg.add_button("Save", RESP_SAVE)
+        _header = Gtk.HeaderBar()
-        self.dlg.add_button("Save & Restart", RESP_SAVE_RESTART)
+        _header.set_show_close_button(True)
+        _header.set_title("Blitztext — Settings")
+        _save_restart = Gtk.Button(label="Save & Restart")
+        _save_restart.get_style_context().add_class("suggested-action")
+        _save_restart.connect("clicked", lambda _b: self.dlg.response(RESP_SAVE_RESTART))
+        _header.pack_end(_save_restart)
+        _save = Gtk.Button(label="Save")
+        _save.connect("clicked", lambda _b: self.dlg.response(RESP_SAVE))
+        _header.pack_end(_save)
+        _header.show_all()
+        self.dlg.set_titlebar(_header)
 
         _prov = Gtk.CssProvider()
         _prov.load_from_data(b"""
@@ -2672,6 +2685,7 @@ notebook.bt-nb tab:checked label {
                 self._cleanup()
                 os.execv(sys.executable, [sys.executable, "-m", "blitztext", "tray"])
             return
+        # X button / window close
         self._cleanup()
         dlg.destroy()