feat(editor): show contour direction and first point in the object tree

[kostyafarber]

Summary

• Closed contours in the Objects tree show their winding direction (Lucide rotate icons). The icon appears on hover and stays visible while the contour is selected. Clicking it reverses that contour as one undoable step without changing the selection; the canvas "Reverse Contour" command now uses the same reverseContours helper.
• The first point of each contour has its own triangle icon.
• Selecting a contour highlights its point rows as one block, matching how a selected category covers its subcategories in the glyph catalog, and draws its point handles as selected on the canvas. The selection still holds only the contour id, so contour commands (reverse, boolean ops, dragging the whole contour) are unchanged.
• The tree no longer shows the browser focus outline when a key such as Shift is pressed after a click. The focused row gets a ring only during arrow/Home/End navigation.

Issue

Closes #484

Testing

• pnpm check (typecheck, lint, all unit tests)
• New unit tests: contour direction for clockwise, counter-clockwise and open contours, plus the first-point icon (createObjectTree.test.ts); a selected contour draws all its handles as selected (GlyphHandleStates.test.ts, confirmed failing without the change)
• Manual check in the app: hover/selected visibility, reversing without selection change, dragging a contour selected from the tree, the triangle's weight next to the point icons
• E2E not run locally. editor.spec.ts "selects displayed glyph objects from the Objects tab" has goldens (objects-sidebar.png, objects-sidebar-selection.png) that should change because of the first-point icon. They need regenerating and inspecting on CI.

Follow-up

• Screenshots of the hover, selected and covered-row states still need attaching before review.