feat(cv): rebuild professional resume studio

docs/architecture/cv-theme-engine.md

@@ -24,15 +24,19 @@ which is retained only for the legacy tailored-draft flow and is not used by the
 | Spacing | `PageMarginMm`, `SectionGapMm`, `EntryGapMm` |
 | Styling | `HeaderStyle` (`plain`\|`band`\|`centered`\|`kicker`), `HeadingStyle` (`caps-rule`\|`underline`\|`plain`\|`bar`), `PhotoShape` (`none`\|`square`\|`rounded`\|`circle`), `DefaultIcons` |
 
-The renderer computes CSS variables from these plus the variant's runtime overrides (accent, fonts,
-density, page size, photo, icons) and picks one of the layout wrappers. `SidebarSections` decides which
-section keys move to the sidebar for the two-column layouts.
+The renderer computes CSS from these plus normalized variant overrides: printable palette, curated
+fonts, body/heading size, line height, spacing, page size, layout, sidebar width/content, header and
+heading treatments, skills presentation, photo and icons. `SidebarSections` decides which section
+keys move to the sidebar for the two-column layouts. Changing a template or override never transforms
+the structured career content.
 
 ## Adding a theme
 
 1. Append one `CvTheme { … }` to `CvThemeCatalog.Themes` (`JobTrackerApi/Models/CvTheme.cs`). Only override the
    fields that differ from the defaults.
-2. Nothing else. It appears in `GET /api/cv/themes`, the Customize tab picker, and renders.
+2. Nothing else. It appears in `GET /api/cv/themes`, the Template tab and dashboard create flow.
+   `GET /api/cv/themes/{id}/preview` renders isolated in-memory sample data for a real visual thumbnail;
+   preview data is never persisted.
 
 Add a `CvBuilderTests.Every_catalog_theme_renders_valid_html` already loops the whole catalog, so a new
 theme is smoke-tested automatically.