feat(docs): version-based docs, correct Gitea tag links, form guide help

- each release now carries a full docs snapshot (reference + handbook)
  under docs/releases/<v>/; the docs frontend loads a version's snapshot
  for /docs/vX.Y.Z/* and shows the handbook/reference of that version
- version dropdown navigates to /docs/<version> (docs home) instead of
  the release notes page; old /docs/vX.Y.Z redirect removed
- generator: --snapshot writes handbook + reference; build copies
  versioned snapshots (last 7 versions) into /docs/versions/<v>/
- fix Gitea tag links: /admin/tool-evaluator/tags/<v> was 404, correct
  URL is /releases/tag/<v>
- add GuideHelp button to forms/pages linking to the matching handbook
  guide (rating, tool add/edit, costs, compare, watchlist, analytics)

artifacts/toolrate/src/components/guide-help.tsx

@@ -0,0 +1,29 @@
+import { BookOpen } from "lucide-react";
+import { Link } from "wouter";
+import { Tooltip, TooltipContent, TooltipTrigger } from "@/components/ui/tooltip";
+
+export function GuideHelp({
+  guide,
+  label,
+}: {
+  guide: string;
+  label: string;
+}) {
+  return (
+    <Tooltip>
+      <TooltipTrigger asChild>
+        <Link
+          href={`/docs/handbook/${guide}`}
+          target="_blank"
+          rel="noreferrer"
+          aria-label={`Help: ${label}`}
+          data-testid={`guide-${guide}`}
+          className="inline-flex shrink-0 text-muted-foreground hover:text-foreground transition-colors"
+        >
+          <BookOpen className="h-3.5 w-3.5" />
+        </Link>
+      </TooltipTrigger>
+      <TooltipContent>{label} — Anleitung in der Dokumentation</TooltipContent>
+    </Tooltip>
+  );
+}