refactor: UI consistency — shared CSS, design system colors, no inline styles

Phase 1: Extract 6 shared CSS modules (table-section, log-panel,
rate-colors, refresh-indicator, chart-card, section-card) eliminating
~135 duplicate class definitions across 11 files.

Phase 2: Replace all hardcoded hex colors in CSS modules with design
system variables. Strip ~55 hex fallbacks from var() patterns. Fix 4
undefined variable names (--accent, --bg-base, --surface, --bg-surface-raised).

Phase 3: Replace ~45 hardcoded hex values in ProcessDiagram SVG
components with var() CSS custom properties. Fix Dashboard.tsx color prop.

Phase 4: Create CSS modules for AdminLayout, DatabaseAdminPage,
OidcCallback (previously 100% inline). Extract shared PageLoader
component (replaces 3 copy-pasted spinner patterns). Move AppsTab
static inline styles to CSS classes. Extract LayoutShell StarredList styles.

58 files changed, net -219 lines.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/pages/Dashboard/Dashboard.module.css

@@ -34,16 +34,16 @@
   height: 18px;
   margin-left: 4px;
   border: none;
-  background: var(--bg-hover, #F5F0EA);
-  color: var(--text-secondary, #5C5347);
+  background: var(--bg-hover);
+  color: var(--text-secondary);
   border-radius: 50%;
   cursor: pointer;
   padding: 0;
 }
 
 .clearSearch:hover {
-  background: var(--border, #E4DFD8);
-  color: var(--text-primary, #1A1612);
+  background: var(--border);
+  color: var(--text-primary);
 }
 
 .tableRight {
@@ -109,8 +109,8 @@
   width: 6px;
   height: 6px;
   border-radius: 50%;
-  background: #5db866;
-  box-shadow: 0 0 4px rgba(93, 184, 102, 0.4);
+  background: var(--success);
+  box-shadow: 0 0 4px color-mix(in srgb, var(--success) 40%, transparent);
   flex-shrink: 0;
 }