…uite (1.3.4)

Refactor — pure consolidation, ~210 lines deleted:
- ThemeManager preference reads now route through CFPreferencesCopyAppValue
  with the main app's bundle ID rather than UserDefaults.standard. The QL
  extension's sandbox has its own UserDefaults domain (empty for these
  keys) but reads the same on-disk plist via CFPreferences as the main
  app. Setters keep the UserDefaults + persistPref pair so the main
  app's in-process cache stays warm.
- project.yml's QLPlugin target now compiles Sources/UI/MarkdownViewController
  and its dependencies (TOCFloatingView, OpenWithButton, ReloadBannerView,
  TextInteractionHandler, FragmentLinkHandler, FontSizeManager) plus
  Sources/Platform/FileWatcher. Same source files, two targets.
- PreviewViewController slimmed from 263 → 53 lines. It hosts a
  MarkdownViewController as a child VC; everything else (theme
  resolution, scroll view, render, themed Open button) comes from the
  shared MVC.
- AppDelegate's first-render hook decoupled from MarkdownViewController
  via NotificationCenter so MVC compiles into both targets.
- QL preview now inherits: TOC sidebar, article-width cap, themed
  Open button with hover, fragment link resolution, scroll-position
  sync, smart typography, code-block fixes — without per-target drift.

Tests added — Sources/Tests/, 47 cases passing:
- BlockSplitter: fence-aware splitting, blank-line handling.
- SmartTypography: quotes / em-dash / en-dash / ellipsis curling,
  skip rules for code spans / fenced blocks / link URLs / GFM tables.
- FragmentLinkHandler: GitHub-style slug, idempotence, lookup.
- TOCBuilder: heading extraction order and trimming.
- MarkdownRenderer: heading-level attributes, smart-typo opt-out,
  leading-newline strip in code blocks.
- ThemeManager: CFPreferences fallback + actual read of user-set
  preferences (validates the migration above).
- MarkdownViewController: init from URL + loadView smoke tests.
- PreviewHostingContract: end-to-end render → TOCBuilder pipeline
  matches between main app and QL preview.

CI:
- release.yml now runs `swift test` before xcodebuild Release. Failing
  tests block the release.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>