fix(planner): steady satellite pill, responsive places rail, day-scoped add

The satellite toggle sat on an offset that included --day-panel-h, so it hopped
every time the day panel was collapsed or expanded. On the desktop map that
panel is a centred card between the sidebars and never reaches the pill at the
left edge, so the lift only applies on a phone now.

In the places rail the two add buttons split the width evenly once a day is
open, and every button drops to its icon when the rail is dragged narrow. The
filter tabs span the rail and keep their own text widths. The count is a badge
across the rail; the search field got the outline the controls around it use.

An empty day offers a button that opens the place form pointed at that day
instead of only stating that nothing is planned. The day is cleared again when
the form is opened to edit, which it was not before.

The trip tab bar no longer carries a native title repeating its own label; the
full name moved to aria-label for the tabs whose label is abbreviated.

Three maps tests drove the index switch through app_settings, which no longer
holds it, and now move TREK_PLACES_ENABLED instead.

client/src/components/shared/SlidingTabs.tsx

@@ -3,7 +3,18 @@ import React, { useLayoutEffect, useRef, useState, type CSSProperties } from 're
 export interface SlidingTab<T extends string> {
   id: T
   label: React.ReactNode
+  /**
+   * Native tooltip. Opt-in and never derived from the label: a tooltip that only
+   * repeats the text next to the cursor is noise, so a caller sets this solely
+   * when the tab shows something the label does not spell out.
+   */
   title?: string
+  /**
+   * Accessible name, for a tab whose visible label is an abbreviation. Silent on
+   * screen, unlike `title`, so it carries the full name without putting a
+   * tooltip under the cursor.
+   */
+  ariaLabel?: string
   icon?: React.ComponentType<{ size?: number; className?: string }>
   count?: number
 }
@@ -130,7 +141,8 @@ export function SlidingTabs<T extends string>({
             ref={el => { tabRefs.current.set(tab.id, el) }}
             onClick={() => onChange(tab.id)}
             style={btnStyle}
-            title={tab.title ?? (typeof tab.label === 'string' ? tab.label : undefined)}
+            title={tab.title}
+            aria-label={tab.ariaLabel}
           >
             {Icon && <Icon size={size === 'sm' ? 13 : 15} />}
             {tab.label}