blog: three curated series across the whole catalogue + badge on post pages

Extends the lone security thread into three arcs that read as skill pillars -
SECURITY (6), NETWORKING (5), PLATFORM (7) - so every post carries a numbered
badge and the catalogue advertises three areas of depth rather than a loose
list. Adds the badge to the post detail header too, styled to match the cards.

src/data/series.ts

@@ -1,7 +1,34 @@
-// Post series — numbered badges on blog cards. Keyed by post slug.
-// The security series threads the zero-trust arc across posts as they publish.
+// Post series - numbered badges on blog cards, keyed by post slug.
+//
+// Three arcs, each a skill pillar the site advertises. A post carries exactly
+// ONE badge; the number is its reading order within the arc (curated, not by
+// date). New posts pick their series at draft time - see the blog-writing skill.
+//
+//   SECURITY   - identity, secrets, least-privilege, blast-radius (zero-trust)
+//   NETWORKING - Cilium/eBPF, edge exposure, TLS, load-balancing
+//   PLATFORM   - GitOps delivery, immutable infra, operations, DR
 export const series: Record<string, { name: string; number: number }> = {
+  // SECURITY SERIES - the zero-trust spine
   "secret-zero": { name: "SECURITY SERIES", number: 1 },
-  "broker-pattern": { name: "SECURITY SERIES", number: 2 },
-  "workload-least-privilege": { name: "SECURITY SERIES", number: 3 },
+  "workload-least-privilege": { name: "SECURITY SERIES", number: 2 },
+  "broker-pattern": { name: "SECURITY SERIES", number: 3 },
+  "authentik-sso-2fa": { name: "SECURITY SERIES", number: 4 },
+  "one-doorman-many-doors": { name: "SECURITY SERIES", number: 5 },
+  "clone-not-keys": { name: "SECURITY SERIES", number: 6 },
+
+  // NETWORKING SERIES - the eBPF datapath and the edge
+  "landing-on-cilium": { name: "NETWORKING SERIES", number: 1 },
+  "observe-first-deny-second": { name: "NETWORKING SERIES", number: 2 },
+  "snat-ate-my-source": { name: "NETWORKING SERIES", number: 3 },
+  "outbound-only-exposure": { name: "NETWORKING SERIES", number: 4 },
+  "cert-couldnt-see-its-proof": { name: "NETWORKING SERIES", number: 5 },
+
+  // PLATFORM SERIES - how the fleet is delivered and kept alive
+  "shipping-this-site": { name: "PLATFORM SERIES", number: 1 },
+  "no-ssh": { name: "PLATFORM SERIES", number: 2 },
+  "bastion-is-a-pattern": { name: "PLATFORM SERIES", number: 3 },
+  "init-gating-gpu-readiness": { name: "PLATFORM SERIES", number: 4 },
+  "sleep-half-the-fleet": { name: "PLATFORM SERIES", number: 5 },
+  "restore-or-rumour": { name: "PLATFORM SERIES", number: 6 },
+  "stage-the-locks": { name: "PLATFORM SERIES", number: 7 },
 };

src/pages/blog/[slug].astro

@@ -2,6 +2,7 @@
 import Layout from "../../layouts/Layout.astro";
 import { getPosts, formatDate } from "../../lib/blog";
 import { readingTime } from "../../lib/reading";
+import { series } from "../../data/series";
 import { render } from "astro:content";
 import type { GetStaticPaths } from "astro";
 
@@ -21,6 +22,12 @@ const { Content } = await render(entry);
 
       <header class="post__head" data-reveal>
         <div class="post__meta mono">
+          {series[entry.id] && (
+            <>
+              <span class="post__series">{series[entry.id].name} · {String(series[entry.id].number).padStart(2, "0")}</span>
+              <span class="post__sep">·</span>
+            </>
+          )}
           <time datetime={entry.data.date.toISOString()}>{formatDate(entry.data.date)}</time>
           <span class="post__sep">·</span>
           <span>{readingTime(entry.body)}</span>
@@ -87,6 +94,16 @@ const { Content } = await render(entry);
     color: var(--text-faint);
     display: flex;
     gap: 0.5rem;
+    align-items: center;
+    flex-wrap: wrap;
+  }
+  .post__series {
+    color: var(--accent-2);
+    border: 1px solid var(--border-magenta);
+    border-radius: 3px;
+    padding: 2px 7px;
+    letter-spacing: 0.1em;
+    font-size: 0.66rem;
   }
   .post__sep {
     opacity: 0.6;