feat(street-level): movable, simplified panel with the photo first

- The viewer opens at the top of the panel, under the header, so the photo
  is on screen without scrolling; its tools (EXPAND, FIT/FILL, FOLLOW, close)
  sit in a bar above the image, clear of the provider's own overlays, and the
  caption wraps instead of truncating.
- No separate ON/OFF or OPEN NEAREST PHOTO buttons: the header pill is the
  layer switch, and a provider chip is lit only while the layer is on (the
  last lit chip switches the layer off).
- SINCE is a stepped slider (any date to the last month) whose readout names
  the cut-off date and is announced via aria-valuetext.
- The panel floats and resizes (portable spec); in a resized window the
  viewer takes the spare height and only the settings scroll. SHRINK after
  EXPAND, collapsing, or a header double-click docks it at its default size.
- FIT/FILL tooltips say what they do.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/ui/applicationShell.js

@@ -950,6 +950,7 @@ export class StyleManager extends ShellFacade {
           }),
         setPanelCollapsed: (collapsed, options) =>
           this.setPanelCollapsed('street-level-panel', collapsed, options),
+        dockPanel: () => this._panelChrome.dockPanel('street-level-panel'),
         showToast: (message) => this._showToast(message),
       },
     });
@@ -1497,13 +1498,15 @@ export class StyleManager extends ShellFacade {
   }
 
   /**
-   * A portable panel finished a resize or snapped back to its rail. Nothing
-   * in the shell depends on it yet; a panel with a viewport of its own can
-   * refit here.
-   * @param {string} _panelId
+   * A portable panel finished a resize or snapped back to its rail. A panel
+   * with a viewport of its own refits here.
+   * @param {string} panelId
    * @returns {void}
    */
-  _onPanelResized(_panelId) {}
+  _onPanelResized(panelId) {
+    if (panelId === 'street-level-panel')
+      this._streetLevelControls?.onPanelResized();
+  }
 
   /**
    * Recalculates the CCTV panel max-height based on its current top position