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)

scripts/src/generate-docs.mjs

@@ -196,7 +196,7 @@ function slugify(name) {
   return name.replace(/\.md$/, "").toLowerCase().replace(/[^a-z0-9-]+/g, "-");
 }
 
-async function buildHandbookIndex() {
+async function readHandbookPages() {
   let files;
   try {
     files = (await readdir(handbookDir)).filter(isHandbookFile);
@@ -213,13 +213,35 @@ async function buildHandbookIndex() {
       file,
       title: frontmatter.title ?? extractTitle(body) ?? basename(file),
       order: typeof frontmatter.order === "number" ? frontmatter.order : 999,
+      body,
     });
-    await writeFile(join(targetDir, "handbook", file), body);
   }
   pages.sort((a, b) => a.order - b.order || a.title.localeCompare(b.title));
   return pages;
 }
 
+async function writeHandbookTo(dir) {
+  const pages = await readHandbookPages();
+  await mkdir(dir, { recursive: true });
+  for (const page of pages) {
+    await writeFile(join(dir, page.file), page.body);
+  }
+  await writeFile(
+    join(dir, "index.json"),
+    JSON.stringify(
+      pages.map(({ slug, file, title, order }) => ({ slug, file, title, order })),
+      null,
+      2,
+    ),
+  );
+  return pages;
+}
+
+async function buildHandbookIndex() {
+  const pages = await writeHandbookTo(join(targetDir, "handbook"));
+  return pages;
+}
+
 // ---------------------------------------------------------------------------
 // Search index
 // ---------------------------------------------------------------------------
@@ -295,7 +317,8 @@ async function writeSnapshot(version) {
   const dir = join(releasesDir, version);
   await mkdir(dir, { recursive: true });
   await writeFile(join(dir, "reference.json"), JSON.stringify(reference, null, 2));
-  console.log(`[generate-docs] snapshot ${version} -> ${join(dir, "reference.json")}`);
+  await writeHandbookTo(join(dir, "handbook"));
+  console.log(`[generate-docs] snapshot ${version} -> ${dir}/ (reference.json + handbook)`);
 }
 
 // ---------------------------------------------------------------------------
@@ -343,27 +366,48 @@ async function main() {
     JSON.stringify(handbookPages, null, 2),
   );
 
-  // 3. Release notes + versioned reference snapshots
+  // 3. Release notes + versioned docs snapshots (last 7 versions)
   const versions = [];
-  for (const name of releaseNames) {
+  for (const name of releaseNames.slice(0, 7)) {
     const version = parseVersion(name);
     const content = await readFile(join(releasesDir, name), "utf8");
     await copyFile(join(releasesDir, name), join(targetDir, "releases", name));
-    const hasSnapshot = await stat(join(releasesDir, version, "reference.json"))
+    const snapDir = join(releasesDir, version);
+    const hasReference = await stat(join(snapDir, "reference.json"))
       .then(() => true)
       .catch(() => false);
-    if (hasSnapshot) {
+    const hasHandbook = await stat(join(snapDir, "handbook", "index.json"))
+      .then(() => true)
+      .catch(() => false);
+    if (hasReference) {
       await copyFile(
-        join(releasesDir, version, "reference.json"),
+        join(snapDir, "reference.json"),
         join(targetDir, "versions", `${version}.json`),
       );
     }
+    if (hasHandbook) {
+      await mkdir(join(targetDir, "versions", version, "handbook"), { recursive: true });
+      await copyFile(
+        join(snapDir, "handbook", "index.json"),
+        join(targetDir, "versions", version, "handbook", "index.json"),
+      );
+      const pages = JSON.parse(
+        await readFile(join(snapDir, "handbook", "index.json"), "utf8"),
+      );
+      for (const page of pages) {
+        await copyFile(
+          join(snapDir, "handbook", page.file),
+          join(targetDir, "versions", version, "handbook", page.file),
+        );
+      }
+    }
     versions.push({
       version,
       file: `releases/${name}`,
       title: extractTitle(content) ?? version,
       date: extractDate(content) ?? null,
-      hasReference: hasSnapshot,
+      hasReference,
+      hasHandbook,
     });
   }