feat(todo): side panes widen by their line, and a tap adds a task (ADR 0033, D33)

The line beside the task pane and Today's Plan is dragged, between 300 px
for the pane and 360 px beside it, each pane's width kept on the device.
A tap or click in the hour grid opens quick add at the quarter hour under
it, on a phone too, as where it lands says when; a long press takes
quarter hours as well. A tap that stops the day scrolling adds nothing.

Whats-New: Drag the line beside a task or the Plan to resize it; tap or click into the calendar to add a task at that time.
Whats-New-De: Ziehe die Linie neben einer Aufgabe oder dem Plan, um die Breite zu ändern; tippe oder klicke in den Kalender, um dort eine Aufgabe anzulegen.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

docs/adr/0033-halkyon-todo.md

@@ -714,6 +714,22 @@ The developer's review of 4 Nov 2026, again beside Todoist's screens.
    - Android's backup and transfer to another phone are off, as Train's D53 (agent's
      choice): the reminders scheduled keep their tasks' titles unsealed on the phone.
 
+- **D33 Side panes widened, a click adds a task** (the developer's, 5 Nov 2026, from
+  Todoist's desktop app; the details the agent's):
+  - The line beside the task pane (D2) and Today's Plan (D30) is dragged left and right
+    (`SidePane`), so wherever a pane stands beside a list or a calendar. A pane stays
+    300 px wide at least and leaves 360 px beside it; a window too narrow for the width
+    chosen shows less of it, and the choice stays. Each pane keeps its own width
+    (`PaneWidths`, the file `panes.json`): widths belong to a window, so they are the
+    device's, neither sealed nor synced, as the device's look is. One width for both was
+    the alternative; the Plan starts narrower than a task.
+  - In the hour grid (`HourGrid`, so Today's calendar and Upcoming's 3-day) a tap or a
+    click opens quick add at the quarter hour under it, for half an hour, on a phone
+    too: a list's or board's + is dragged for the place between tasks, while in a
+    calendar where it lands already says when. A long press stays, in quarter hours,
+    no more half hours. A tap that stops the day scrolling doesn't add, as a fling
+    keeps pointers from what it scrolls.
+
 ## Consequences
 
 - No email reminder, morning overview or evening review: the server can't read what is