fix(dimension): oblique and architectural-tick arrow blocks fit as ticks

Only DIMTSZ > 0 counted as ticks, so a style drawing its strokes with
the _OBLIQUE / _ARCHTICK arrow block gave each stroke a full arrow's
room: an 18-long dimension with 4.8 arrows moved its strokes outside
and ran the dim line past the extension lines once it was drawn live
(after any edit, #898). Tick arrow blocks now count as ticks for fit
and DIMDLE, like the file's own baked block shows them.

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

src/entities/dimension.rs

@@ -3842,7 +3842,13 @@ fn tessellate_dimension_inner(
             dimfxlon,
             dimsoxd,
             dimcen,
-            ticks: dimtsz_raw > 1e-9,
+            // Oblique-stroke and architectural-tick arrow blocks are ticks
+            // too: they sit on the extension line and need no room of their
+            // own, and DIMDLE applies to them. Given arrow-sized room, an
+            // 18-long dimension flipped its strokes outside (#898).
+            ticks: dimtsz_raw > 1e-9
+                || (matches!(arrow1, ArrowKind::Tick { .. })
+                    && matches!(arrow2, ArrowKind::Tick { .. })),
             arrow_len: dimasz,
             text_width: text_layout.width,
             text_height: dim_txt as f32,