fix: repair broken links after Jekyll-to-Hugo restructure

- Extend image ignorePattern in markdown-link-check.json to cover all
  /images/*.png (covers ui-settings, ui-devices, ui-sync, ui-migration,
  speaker-ap-wifi-setup that live under docs/static/images/ but are
  referenced as absolute /images/ paths in Markdown)
- Fix appendix cross-section links: add ../ prefix to guides/, reference/,
  and analysis/ paths in PRESET-QUICKSTART, SOUNDTOUCH-SERVICE-ANNOUNCEMENT,
  CONTENT-SELECTION-IMPLEMENTATION, DEVICE-LOGGING, NAVIGATION-GUIDE,
  PARITY-SOUNDCORK, and CLAUDE.md
- Convert ../examples/* relative links in appendix to GitHub URLs (the
  examples/ dir is at repo root, not under docs/content/)
- Fix CLAUDE.md in appendix: archive/PLAN.md → ../../../archive/PLAN.md;
  remove dead PDF link
- Fix TROUBLESHOOTING.md: ../DEVICE-LOGGING.md → ../appendix/DEVICE-LOGGING.md
- Fix CAPTURE-DEVICE-PAIRING.md: ../DEVICE-SETUP.md → ../appendix/DEVICE-SETUP.md
- Fix RASPBERRY-PI.md: remove accidental ../ prefix from GitHub URL
- Fix CONTRIBUTING.md: update docs/reference/ and docs/PROJECT-PATTERNS.md
  to their new paths under docs/content/docs/
- Fix README.md: update deployment overview link to new path
- Fix BASS-CONTROLS.md and SOURCE-SELECTION.md: convert ../../pkg/models/
  relative links to GitHub URLs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/markdown-link-check.json

@@ -27,7 +27,7 @@
       "pattern": "^https://pkg.go.dev.*badge"
     },
     {
-      "pattern": "^/images/(dashboard-home|account-creation|account-dashboard|usb-remote-services|device-discovery|device-registration|account-migration|migration-setup|migration-progress|migration-health|migration-complete|backup-setup)\\.png$"
+      "pattern": "^/images/[^/]+\\.png$"
     },
     {
       "pattern": "https://www.contributor-covenant.org/version/2/0/code_of_conduct.html"