feat(docs): add changelog page and switch tag guide paths to appendix

apps/docs/lib/releases.ts

@@ -0,0 +1,94 @@
+/**
+ * The `/changelog` page's data: every timever release apps/cli/release-topics.ts
+ * published — one per finished topic and per finished `Review <N>` issue —
+ * read from the GitHub API at build time (pages/changelog.astro awaits it).
+ *
+ * One page, no per-release subpages: each release becomes one timeline card,
+ * so the fields come from the release itself rather than a staged content
+ * entry. The date is the timever tag (`YYYYMMDD.HHMMSS.NNNNNNNNN`, UTC — the
+ * instant the last required problem closed), never `published_at`, which the
+ * API cannot backdate and which reads the backfill day for every old release.
+ * The problems are the rows of the body's `### Closed …` tables, the shape
+ * release-topics.ts's render() writes: `| #issue | LC n · Name | set | diff |
+ * closed | [py](…) · [docs](…) |`. Only `### Closed …` sections are read, so
+ * a release published before open problems were dropped from the body still
+ * shows only what finished.
+ *
+ * Auth: GITHUB_TOKEN when set (deploy.yml passes it), else unauthenticated —
+ * one request per 100 releases fits the anonymous limit. A failed request
+ * fails the build: a changelog silently missing its releases is worse.
+ */
+
+const REPO = "prdlk/leetcode";
+const MARKER = /<!-- release-topics: #(\d+) -->/u;
+const TIMEVER = /^(\d{4})(\d{2})(\d{2})\.(\d{2})(\d{2})(\d{2})\.\d{9}$/u;
+const KIND = /^(Topic|Review) \d+ — /u;
+
+export interface ReleaseProblem {
+  issue: number;
+  /** `LC 57 · Insert Interval`. */
+  title: string;
+  set: string;
+  /** `easy` / `medium` / `hard`, the problem's `diff:*` label. */
+  difficulty: string;
+  /** The problem's `/<num>` docs short link, once it has a page. */
+  docs?: string;
+}
+
+export interface Release {
+  /** Topic or Review issue the release records. */
+  issue: number;
+  name: string;
+  kind: "Topic" | "Review";
+  /** UTC instant the last required problem closed, from the timever tag. */
+  finishedAt: Date;
+  url: string;
+  problems: ReleaseProblem[];
+}
+
+/** Rows of every `### Closed …` table in a release body. */
+function closedProblems(body: string): ReleaseProblem[] {
+  const problems: ReleaseProblem[] = [];
+  let closed = false;
+  for (const line of body.split("\n")) {
+    if (line.startsWith("### ")) closed = line.startsWith("### Closed");
+    if (!closed || !line.startsWith("| #")) continue;
+    const [issue, title, set, difficulty, , solution] = line.slice(1, -1).split("|").map((cell) => cell.trim());
+    if (!issue || !title || !set || !difficulty) continue;
+    problems.push({
+      issue: Number(issue.slice(1)),
+      title,
+      set,
+      difficulty,
+      docs: solution?.match(/\[docs\]\(([^)]+)\)/u)?.[1],
+    });
+  }
+  return problems;
+}
+
+export async function readReleases(): Promise<Release[]> {
+  const headers: Record<string, string> = { accept: "application/vnd.github+json" };
+  if (process.env.GITHUB_TOKEN) headers.authorization = `Bearer ${process.env.GITHUB_TOKEN}`;
+  const releases: Release[] = [];
+  for (let page = 1; ; page++) {
+    const res = await fetch(`https://api.github.com/repos/${REPO}/releases?per_page=100&page=${page}`, { headers });
+    if (!res.ok) throw new Error(`GET ${REPO} releases -> ${res.status} ${await res.text()}`);
+    const batch = (await res.json()) as { tag_name: string; name: string | null; body: string | null; html_url: string }[];
+    for (const r of batch) {
+      const issue = r.body?.match(MARKER)?.[1];
+      const t = r.tag_name.match(TIMEVER);
+      const kind = r.name?.match(KIND)?.[1];
+      if (!issue || !t || !kind || !r.name || !r.body) continue;
+      releases.push({
+        issue: Number(issue),
+        name: r.name,
+        kind: kind as Release["kind"],
+        finishedAt: new Date(`${t[1]}-${t[2]}-${t[3]}T${t[4]}:${t[5]}:${t[6]}Z`),
+        url: r.html_url,
+        problems: closedProblems(r.body),
+      });
+    }
+    if (batch.length < 100) break;
+  }
+  return releases.sort((a, b) => b.finishedAt.getTime() - a.finishedAt.getTime());
+}

apps/docs/pages/changelog.astro

@@ -0,0 +1,117 @@
+---
+/**
+ * `/changelog`: every topic and review release on one page, newest first — a
+ * vertical timeline, the date on the left and one card per release on the
+ * right, with no per-release subpages. Replaces Blume's generated changelog
+ * (a custom page wins its route); the header links here from
+ * `navigation.actions` in blume.config.ts. Data: lib/releases.ts.
+ */
+import PageLayout from "blume/components/layout/PageLayout.astro";
+import data from "blume:data";
+import { readReleases } from "../lib/releases.ts";
+
+const { config } = data;
+const releases = await readReleases();
+const DATE = new Intl.DateTimeFormat("en-US", {
+  timeZone: "America/New_York",
+  month: "short",
+  day: "numeric",
+  year: "numeric",
+});
+const issueUrl = (n: number) => `https://github.com/prdlk/leetcode/issues/${n}`;
+// The /progress cards' difficulty palette (--chart-1..3 in theme.css), so a
+// Hard reads the same colour here as in the SolvedRing gauge.
+const DIFFICULTY: Record<string, { label: string; class: string }> = {
+  easy: { label: "Easy", class: "border-chart-1/40 bg-chart-1/10 text-chart-1" },
+  medium: { label: "Med.", class: "border-chart-2/40 bg-chart-2/10 text-chart-2" },
+  hard: { label: "Hard", class: "border-chart-3/40 bg-chart-3/10 text-chart-3" },
+};
+const description = "Every topic and review the campaign finished, newest first.";
+---
+
+<PageLayout
+  site={{ title: config.title, description: config.description }}
+  logo={config.logo}
+  favicon={config.favicon}
+  banner={config.banner}
+  analytics={config.analytics}
+  navigation={data.navigation}
+  fontCssVars={data.fontCssVars}
+  themeMode={config.theme.mode}
+  searchEnabled={config.search.enabled}
+  siteUrl={config.site}
+  ogEnabled={config.og.enabled}
+  structuredDataEnabled={config.structuredData}
+  page={{ title: `Changelog - ${config.title}`, description, route: "/changelog" }}
+>
+  <section class="mx-auto w-full max-w-4xl px-6 py-16">
+    <h1 class="m-0 text-4xl font-semibold tracking-tight text-foreground">Changelog</h1>
+    <p class="mt-3 text-lg text-muted-foreground">{description}</p>
+
+    <ol class="relative mt-12 list-none p-0">
+      {
+        releases.map((r, i) => (
+          <li class="relative grid gap-4 pb-14 pl-8 sm:grid-cols-[11rem_1fr] sm:gap-8">
+            {/* The rail: a line down the left edge, a ring at each release. */}
+            {i < releases.length - 1 && (
+              <span class="absolute top-3 bottom-0 left-[5px] w-px bg-border" aria-hidden="true" />
+            )}
+            <span
+              class="absolute top-1.5 left-0 size-[11px] rounded-full border border-emerald-500 bg-background"
+              aria-hidden="true"
+            />
+            <div class="font-mono text-sm">
+              <time class="block uppercase tracking-wide text-foreground" datetime={r.finishedAt.toISOString()}>
+                {DATE.format(r.finishedAt)}
+              </time>
+              <a class="mt-1 block text-xs text-muted-foreground no-underline hover:underline" href={r.url}>
+                {r.kind} release ↗
+              </a>
+            </div>
+            <article id={`issue-${r.issue}`} class="rounded-lg border border-border bg-muted/30 p-6">
+              <header class="flex items-baseline justify-between gap-4">
+                <h2 class="m-0 text-lg font-semibold text-foreground">{r.name}</h2>
+                <a
+                  class="shrink-0 font-mono text-sm text-muted-foreground no-underline hover:underline"
+                  href={issueUrl(r.issue)}
+                >
+                  #{r.issue}
+                </a>
+              </header>
+              <ul class="mt-4 mb-0 list-none space-y-2 p-0">
+                {r.problems.map((p) => (
+                  <li class="flex items-baseline gap-3 text-base leading-relaxed text-muted-foreground">
+                    <span class="select-none text-border" aria-hidden="true">—</span>
+                    <span class="min-w-0 flex-1">
+                      <span class="mr-2 font-mono text-xs uppercase tracking-wide">{p.set}</span>
+                      <a class="text-foreground no-underline hover:underline" href={issueUrl(p.issue)}>
+                        {p.title}
+                      </a>
+                      {p.docs && (
+                        <a class="ml-2 font-mono text-xs text-emerald-500 no-underline hover:underline" href={p.docs}>
+                          view →
+                        </a>
+                      )}
+                    </span>
+                    {/* Its own right-hand column, one width for all three, so the
+                        badges line up down the card instead of crowding the link. */}
+                    {DIFFICULTY[p.difficulty] && (
+                      <span
+                        class:list={[
+                          "w-12 shrink-0 rounded-full border py-px text-center font-mono text-[11px] leading-4",
+                          DIFFICULTY[p.difficulty]!.class,
+                        ]}
+                      >
+                        {DIFFICULTY[p.difficulty]!.label}
+                      </span>
+                    )}
+                  </li>
+                ))}
+              </ul>
+            </article>
+          </li>
+        ))
+      }
+    </ol>
+  </section>
+</PageLayout>

apps/docs/topic-landings.ts

@@ -4,10 +4,10 @@
  * tag", read by the sides that must agree:
  *
  * - `components/ProblemBadges.astro` links a covered tag's badge to its
- *   landing page, and every other tag's badge to `/guides/<slug>`;
+ *   landing page, and every other tag's badge to its Appendix guide, `/appendix/<slug>`;
  * - `components/BacklinksList.astro` lists, under a landing or guide page,
  *   every problem whose badge links there — both via `tagTarget()`;
- * - `apps/cli/sync.ts` creates a placeholder `content/guides/<slug>.mdx` for
+ * - `apps/cli/sync.ts` creates a placeholder `content/appendix/<slug>.mdx` for
  *   every tag a problem page carries that is NOT a key here.
  *
  * Add a key when a campaign topic starts teaching a tag; its guide page is then
@@ -61,7 +61,7 @@ export function tagTarget(
   const prefer = page.tags.some((t) => t.slug === "tree") ? "/tree-" : "/graph-";
   const landing = landings.includes(own) ? own : (landings.find((p) => p.startsWith(prefer)) ?? landings[0]);
   if (landing) return { href: landing, kind: "landing" };
-  const guide = `/guides/${tag.slug}`;
+  const guide = `/appendix/${tag.slug}`;
   if (served.has(guide)) return { href: guide, kind: "guide" };
   return { href: `https://leetcode.com/problem-list/${tag.slug}/`, kind: "external" };
 }