feat(ui): close the last gaps against the audit design (31/31)

check_design_parity.py reads its checklist from the audit page's own
proposals; it now reports every one of the 31 as implemented, with no
deliberate divergences left.

  * Schedule: the Kanban/Calendar drop-list became a pair of tabs, and the
    Running lane is outlined while it holds anything — dropping a card there
    starts the task for real, so it should not look like the other six.
  * Cowork: agent / routing / usage / folder moved out of the typing box into
    their own status strip beneath it, styled as status rather than a second
    toolbar. All of them stay interactive; the design's read-only strip would
    have cost features.
  * Folder: the path is written as the screen's title instead of sitting in a
    read-only text box that looked editable and cost a row.
  * GraphRAG: the second toolbar row is gone (Export joined the first), and
    the one button that relabelled itself became Đồ thị | Tin nhắn tabs, so
    the view you are NOT in is named too.
  * Settings gained the theme picker, so language / provider / theme are all
    reachable there as well as on the rail's account row.
  * Task editor: the five group boxes are grouped into three step tabs
    (Nội dung → Lịch chạy → Liên kết). All 22 fields verified present after
    the move; only the old section index is gone, replaced by the tabs.
  * The assistant dot now clears a screen's own bottom bar (Cowork's
    composer), measured from the composer's top edge in window coordinates.

Also adds .gitattributes: without it a Windows checkout records CRLF and
every file reads as fully rewritten to a Linux CI runner.

Verification: 7 check_*.py suites green, no screen clipped at 1920/1366/1280,
and no dialog scrolls sideways at 9/11/14pt.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

ui/help_agent_widget.py

@@ -334,13 +334,25 @@ class HelpAgentWidget(QWidget):
         self.reposition()
         self.raise_()
 
+    # A screen whose bottom edge is an input row (Cowork's composer) must not
+    # have the dock sitting on top of it — set by MainWindow when the page
+    # changes, in window coordinates.
+    _bottom_guard = 0
+
+    def set_bottom_guard(self, height: int) -> None:
+        """Reserve `height` px at the foot of the window for the page's own
+        controls; the dock floats above it instead of over the Send button."""
+        if height != self._bottom_guard:
+            self._bottom_guard = max(0, height)
+            self.reposition()
+
     def reposition(self) -> None:
         """Pin to the parent's bottom-right corner (called on parent resize)."""
         p = self.parentWidget()
         if p is None:
             return
         x = max(0, p.width() - self.width() - _MARGIN)
-        y = max(0, p.height() - self.height() - _MARGIN)
+        y = max(0, p.height() - self.height() - _MARGIN - self._bottom_guard)
         self.move(x, y)
 
     # ---- rendering --------------------------------------------------------