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/components/Fleet/FleetGroupsStrip.tsx

@@ -1,4 +1,5 @@
 import type { FleetGroup } from '../../help/fleetGroups';
+import { HelpTip } from '../HelpTip';
 import './FleetGroupsStrip.css';
 
 interface Props {
@@ -22,7 +23,7 @@ export default function FleetGroupsStrip({
 
   return (
     <div className="fleet-groups-strip card">
-      <span className="fleet-groups-strip-label font-tech">Groups</span>
+      <span className="fleet-groups-strip-label font-tech">Groups <HelpTip field="fl_groups" /></span>
       <div className="fleet-groups-strip-list">
         {groups.map((g) => {
           const onlineInGroup = liveAgentIds