fix: second-wave bug fixes, security hardening, visual polish, UX improvements

Bug fixes:
- SRV-B1 through B5: server config, router, server_info, syscheck corrections
- BA-03 through BA-06: builder path and universal build cleanup (BLD-D1 through D3)
- Frontend WS race condition and useVisibleInterval hook fixed
- Drive-root path bug in PathForge resolved
- Upload error handling improved

Security:
- PathForge path traversal guard added
- Script injection escaping applied throughout

Visual (DV-01 through DV-15):
- Cyan design tokens and page headers standardised
- Dead CSS removed from Pages.css, PathTracerPage.css, wealth-deck.css
- SacredPageHeader deleted (replaced inline); sidebar version display fixed

UX:
- Emberwake request storm fixed (EmberwakePage.tsx)
- Help blurbs UH-01, UH-02, UH-06 added
- HelpTips wired into Crucible, Fleet (FleetGroupsStrip, FleetToolbar), Settings

Build:
- vite.config.ts: webroot auto-sync on build
- build_universal.go: universal build artifact cleanup
- PROBLEMS.md tracking updated

server/web/src/pages/Pages.css

@@ -190,13 +190,17 @@
 
 /* Empty State */
 .empty-state {
+  grid-column: 1 / -1;
   text-align: center;
   padding: 3rem 2rem;
 }
 
 .empty-icon {
   font-size: 3rem;
+  color: var(--brass);
+  opacity: 0.6;
   margin-bottom: 1rem;
+  animation: gear-spin 30s linear infinite;
 }
 
 .empty-state h3 {
@@ -1075,26 +1079,6 @@
   letter-spacing: 0.05em;
 }
 
-.empty-state {
-  grid-column: 1 / -1;
-  text-align: center;
-  padding: 3rem !important;
-}
-
-.empty-icon {
-  font-size: 3rem;
-  color: var(--brass);
-  opacity: 0.6;
-  margin-bottom: 1rem;
-  animation: gear-spin 30s linear infinite;
-}
-
-.page-header h1 {
-  font-family: var(--font-display);
-  font-size: 1.75rem;
-  color: var(--brass-light);
-}
-
 .page-subtitle {
   color: var(--text-secondary);
   font-size: 1rem;