Sketch Dimension: D, click, type (#695)

As soon as a pick settles the dimension (one line, circle or arc, or the second point or line of a distance or angle), its value box takes the keyboard with the measured value selected. The text follows the cursor while typing and Enter places it there (or in its default place), as one undo step. A click before typing pins the text and keeps the box focused, a click on another entity makes a distance or angle, Tab hands back to placing first, Esc cancels. Letters go into the box, not to tool shortcuts.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -101,7 +101,7 @@ rebuild with no errors, replayed here at 2× speed.
   by parameters. Over-constraining edits are rejected; fully constrained geometry turns black.
   Dragging solves the sketch every frame and rebuilds the model once, when the drag ends.
   Select a line or its two endpoints, type its dimension and press Enter to commit one undo
-  step. Fit keeps sketch geometry clear of the palette and navigation controls.
+  step; with Sketch Dimension it's D, click, type, Enter. Fit keeps sketch geometry clear of the palette and navigation controls.
 - **Profiles** found automatically, including regions split by lines and holes inside outlines.
   Newly captured complete adaptive boundaries retain their outer and hole source identities
   when spline span counts change. Partial or ambiguous boundaries do not qualify.