feat(career): theme polish, rich-text bullets, entry ordering, outline API

Phase 4.5 backend enablers.
- Themes (priority 3): AtsFriendly flag on single-column themes (surfaced in
  GET /api/cv/themes), print-quality page-break rules (entries never split
  across a page; headings stay with content; widow/orphan control), darkened
  the creative sidebar for AA contrast.
- Rich text (priority 1): bullets/summary support **bold**, *italic*,
  __underline__, [text](url) via a safe inline pass — everything is HTML-escaped
  first, so no user tag can survive; only the whitelist emits markup.
- Entry ordering (priority 1): CvSectionSetting.ItemOrder reorders entries
  within a section by ItemKey, never touching the master profile.
- Outline API: GET /api/cv/outline returns the master profile as sections+entries
  with ItemKeys, so the Content tab can render editable per-item rows.
- 3 new tests (22 total in the builder suite).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Models/CvVariantSettings.cs

@@ -39,6 +39,10 @@ public sealed class CvSectionSetting
     public string Key { get; set; } = string.Empty; // summary|skills|experience|education|projects|certifications|languages|interests|links|custom:<k>
     public bool Hidden { get; set; }
     public string? Title { get; set; } // renamed heading
+    // Explicit entry order for this section, as a list of item ItemKeys. Entries not listed keep their
+    // master order and come last. Null => master profile order. Lets a variant reorder entries without
+    // touching the master profile.
+    public List<string>? ItemOrder { get; set; }
 }
 
 public sealed class CvItemOverride