SU.1110 CivilCraft: reusable corridor templates and several assemblies on one corridor, with left and right pavement and end conditions set apart

Asked (#1110, Oct 28): templates for roadway and site structures (curb, gutter, sidewalk, retaining walls), as OpenRoads Designer does: a template usable on any element, even applied to terrain surfaces; several templates or assemblies on one corridor; pavement and end conditions controlled left and right separately; small templates reused instead of a custom one per project.

Builds on D7.35 (corridor assemblies) and WL.25 (corridor targets). Do: template library (components with offsets, slopes, materials, point codes); corridor takes a list of templates by station range; left and right pavement and end conditions (daylight to ground, wall, ditch) independent; surface templates for terrain edits (LD.3 grading). Example templates are for checking by an engineer.

**Implementation started 2026-11-02** (0.9 top-5 pick #4, hardest first; session `civil-templates-09`, log docs/0.9-sessions/civil-templates-09.md). Status moves to Partly built or Built only when the code is reachable and tested (rule 49).