fix: use theme brushes for exact-match hardcoded colors in four views

[laurentiu021]

Summary

Replaces hardcoded color literals with theme DynamicResource brushes — but only
where the hex exactly matches an existing theme color, so every color renders identically
today and now tracks the theme going forward.

Changes (11 exact-match replacements, 4 views)

• DashboardView — CPU vitals dot/percent/progress #22C55E→Success; System-Alerts
  severity-dot setters #22C55E→Success, #F59E0B→Warning, #EF4444→Danger.
• NetworkRepairView — hover BorderBrush #2A3244→Border2 on the three repair cards.
• PrivacyView — per-toggle hover BorderBrush #2A3244→Border2.
• UninstallerView — source-badge default Fill #6366F1→Accent.

Safety

• A workflow processed 17 candidate views; agents were instructed to replace a hex only
  on an exact match against the authoritative App.xaml palette, and to skip and report
  anything else. They left 104 non-matching hexes untouched (one-off per-metric accents
  like #3B82F6/#A855F7, and 8-digit ARGB values with alpha) — those would need new
  theme tokens, which is a design decision, not a mechanical swap.
• Each replacement verified against App.xaml: Success=#22C55E, Warning=#F59E0B,
  Danger=#EF4444, Accent=#6366F1, Border2=#2A3244 — byte-identical render.
• Only color values changed; no layout/binding/structure touched.
• Build: main 0 warnings / 0 errors.

fix: → patch release (1.20.21). Protocol C to follow.