Kernel release 6.18.38-rt-cuckoo+: reproducible build, guarded installer

Rebuilt with KBUILD_BUILD_USER/HOST/TIMESTAMP pinned. Without them the kernel
bakes the builder's user@hostname and wall-clock build time into /proc/version,
which publishes operator identity in a public artifact and makes the build
unreproducible. Pinned, anyone can rebuild and diff the bytes — the only trust
story available for an unsigned community kernel.

The installer refuses to run on anything but a Pi 4, refuses a mismatched
image/modules pair (vermagic failure means no /dev/pps0 on a kernel that
otherwise boots fine — silent and miserable to debug), verifies SHA256SUMS,
never touches kernel8.img, and leaves rollback as deleting one config.txt line.

Boot-tested on the Pi: Stratum 1, 273 ns offset, PPS handler confirmed NOT
threaded. Binaries ship as release assets, not in git.

dashboard/src/gpsntp_dashboard/static/fonts/fonts.css

@@ -0,0 +1,57 @@
+/* Self-hosted: this dashboard runs on a LAN and must work with no internet.
+ * Latin subset only — the latin-ext/greek/vietnamese blocks Google serves
+ * would triple the payload for glyphs a status page will never render.
+ *
+ * Atkinson Hyperlegible is the Braille Institute's legibility face. It is
+ * here for a functional reason, not a brand one: it disambiguates 0/O, 1/l/I
+ * and rn/m, which is exactly what you need when reading `+66 ns` or
+ * `2607:f740:e::d3` at a glance from across a room.
+ */
+
+@font-face {
+  font-family: "Atkinson Hyperlegible";
+  font-style: normal;
+  font-weight: 400;
+  font-display: swap;
+  src: url("/static/fonts/atkinson-400.woff2") format("woff2");
+}
+
+@font-face {
+  font-family: "Atkinson Hyperlegible";
+  font-style: normal;
+  font-weight: 700;
+  font-display: swap;
+  src: url("/static/fonts/atkinson-700.woff2") format("woff2");
+}
+
+@font-face {
+  font-family: "Atkinson Hyperlegible Mono";
+  font-style: normal;
+  font-weight: 400;
+  font-display: swap;
+  src: url("/static/fonts/atkinson-mono-400.woff2") format("woff2");
+}
+
+@font-face {
+  font-family: "Atkinson Hyperlegible Mono";
+  font-style: normal;
+  font-weight: 600;
+  font-display: swap;
+  src: url("/static/fonts/atkinson-mono-600.woff2") format("woff2");
+}
+
+@font-face {
+  font-family: "Libre Baskerville";
+  font-style: normal;
+  font-weight: 400;
+  font-display: swap;
+  src: url("/static/fonts/baskerville-400.woff2") format("woff2");
+}
+
+@font-face {
+  font-family: "Libre Baskerville";
+  font-style: normal;
+  font-weight: 700;
+  font-display: swap;
+  src: url("/static/fonts/baskerville-700.woff2") format("woff2");
+}

dashboard/src/gpsntp_dashboard/static/index.html

@@ -171,6 +171,13 @@
 
     <div class="foot-meta">
       <span id="foot-version">gpsntp-dashboard</span>
+      <!-- Anyone reading "PPS locked · ±219 ns" and wondering what that means,
+           or why this box is a Pi and not an appliance, deserves one click to
+           the write-up rather than a search. -->
+      <a class="foot-docs" href="https://cuckoo.warehack.ing" rel="noopener">
+        How this clock works
+        <svg viewBox="0 0 16 16" aria-hidden="true"><path d="M4 8h7M8 5l3 3-3 3"/></svg>
+      </a>
       <span id="foot-updated">—</span>
     </div>
   </footer>

dashboard/src/gpsntp_dashboard/static/style.css

@@ -1,13 +1,34 @@
+@import url("/static/fonts/fonts.css");
+
+/* Supported Systems house style, applied as WARM SHELL / COOL DATA.
+ *
+ * The chrome — background, panels, type, brand accent — comes from
+ * supported.systems: warm near-black, cream text, Libre Baskerville display,
+ * Atkinson Hyperlegible body, brass accent.
+ *
+ * The INSTRUMENTS do not. Cyan, green, amber and red stay exactly as they were,
+ * because on this page those colors carry information: which constellation a
+ * satellite belongs to, whether a source is selected, whether the clock is
+ * healthy. Recoloring them to brass would trade meaning for brand, which on a
+ * status page is a bad trade at any exchange rate.
+ *
+ * So: --brand is for chrome, --accent is for live data. They are different
+ * variables on purpose. Don't merge them.
+ */
 :root {
-  --bg: #0a0e13;
-  --bg-2: #0e141c;
-  --panel: #121a23;
-  --panel-2: #16212d;
-  --border: #21303f;
-  --border-soft: #1a2632;
-  --text: #e7eef5;
-  --muted: #8a99a8;
-  --faint: #57687a;
+  /* shell — warm (supported.systems) */
+  --bg: #171717;
+  --bg-2: #1b1a18;
+  --panel: #232120;
+  --panel-2: #2b2825;
+  --border: #3d382f;
+  --border-soft: #322e28;
+  --text: #eeece8;
+  --muted: #a8a196;
+  --faint: #6f6a61;
+  --brand: #d9a441;      /* brass. chrome, links, brand marks. NOT data. */
+
+  /* instruments — cool (semantic; do not rebrand) */
   --accent: #22d3ee;
   --good: #34d399;
   --warn: #f5a524;
@@ -20,8 +41,15 @@
   --c-sbas: #a3e635;
   --c-qzss: #2dd4bf;
   --c-other: #94a3b8;
+
   --shadow: 0 1px 0 rgba(255, 255, 255, 0.03), 0 12px 30px -18px rgba(0, 0, 0, 0.9);
-  --mono: ui-monospace, "SF Mono", "JetBrains Mono", "Cascadia Code", Menlo, monospace;
+
+  /* Atkinson Hyperlegible: the Braille Institute's legibility face. Chosen for
+   * function before brand — it disambiguates 0/O, 1/l/I, rn/m, which is exactly
+   * what a glanceable status page needs. */
+  --sans: "Atkinson Hyperlegible", system-ui, -apple-system, sans-serif;
+  --serif: "Libre Baskerville", Georgia, serif;
+  --mono: "Atkinson Hyperlegible Mono", ui-monospace, "SF Mono", Menlo, monospace;
 }
 
 * { box-sizing: border-box; }
@@ -29,11 +57,13 @@
 body {
   margin: 0;
   background:
-    radial-gradient(1200px 600px at 80% -10%, rgba(34, 211, 238, 0.06), transparent 60%),
-    radial-gradient(900px 500px at 0% 0%, rgba(52, 211, 153, 0.05), transparent 55%),
+    /* the warm bench light from supported.systems */
+    radial-gradient(1100px 620px at 50% -8%, rgba(217, 164, 65, 0.07), transparent 62%),
+    /* one cool wash, bottom-left, so the instruments feel like instruments */
+    radial-gradient(900px 500px at 0% 100%, rgba(34, 211, 238, 0.04), transparent 58%),
     var(--bg);
   color: var(--text);
-  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
+  font: 15px/1.5 var(--sans);
   -webkit-font-smoothing: antialiased;
   min-height: 100vh;
 }
@@ -47,12 +77,16 @@ svg { width: 1.15em; height: 1.15em; fill: none; stroke: currentColor; stroke-wi
   gap: 16px; padding: 16px 20px;
   border-bottom: 1px solid var(--border-soft);
   position: sticky; top: 0; z-index: 5;
-  background: linear-gradient(var(--bg), rgba(10, 14, 19, 0.86));
+  background: linear-gradient(var(--bg), rgba(23, 23, 23, 0.86));
   backdrop-filter: blur(8px);
 }
 .brand { display: flex; align-items: center; gap: 13px; }
-.brand-icon { width: 30px; height: 30px; color: var(--accent); }
-.brand h1 { font-size: 19px; margin: 0; letter-spacing: 0.3px; font-family: var(--mono); }
+/* The dish is brand chrome, not a reading — brass, not cyan. */
+.brand-icon { width: 30px; height: 30px; color: var(--brand); }
+/* Libre Baskerville, as on supported.systems. The wordmark is the one place a
+   serif belongs on this page; everything that reports a NUMBER stays mono. */
+.brand h1 { font-size: 20px; margin: 0; letter-spacing: 0.2px; font-family: var(--serif);
+  font-weight: 700; }
 .brand-sub { margin: 0; color: var(--muted); font-size: 12.5px; }
 
 .conn { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--muted);
@@ -75,7 +109,7 @@ main { max-width: 1180px; margin: 0 auto; padding: 20px; display: grid; gap: 18p
 .panel-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 14px; }
 .panel-head h2 { font-size: 14px; margin: 0; color: var(--muted); font-weight: 600;
   display: flex; align-items: center; gap: 8px; text-transform: uppercase; letter-spacing: 0.6px; }
-.panel-head h2 svg { color: var(--accent); }
+.panel-head h2 svg { color: var(--brand); }
 
 /* ---------- hero ---------- */
 .hero { display: flex; align-items: center; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
@@ -104,7 +138,7 @@ main { max-width: 1180px; margin: 0 auto; padding: 20px; display: grid; gap: 18p
 .card { background: var(--panel); border: 1px solid var(--border-soft); border-radius: 14px; padding: 14px 15px; }
 .card-head { display: flex; align-items: center; gap: 7px; color: var(--muted); font-size: 12px;
   text-transform: uppercase; letter-spacing: 0.4px; }
-.card-head svg { width: 15px; height: 15px; color: var(--accent); }
+.card-head svg { width: 15px; height: 15px; color: var(--brand); }
 .card-value { font-family: var(--mono); font-size: 25px; font-weight: 650; margin: 7px 0 3px; letter-spacing: 0.3px; }
 .card-value.good { color: var(--good); }
 .card-value.warn { color: var(--warn); }
@@ -179,8 +213,13 @@ main { max-width: 1180px; margin: 0 auto; padding: 20px; display: grid; gap: 18p
 
 /* ---------- footer ---------- */
 .foot { max-width: 1180px; margin: 0 auto; padding: 14px 20px 30px; }
-.foot-meta { display: flex; justify-content: space-between; margin-top: 14px;
-  color: var(--faint); font-size: 12px; font-family: var(--mono); }
+.foot-meta { display: flex; justify-content: space-between; align-items: center; gap: 12px;
+  margin-top: 14px; color: var(--faint); font-size: 12px; font-family: var(--mono); }
+.foot-docs { display: inline-flex; align-items: center; gap: 5px; color: var(--faint);
+  text-decoration: none; transition: color .2s; }
+.foot-docs:hover { color: var(--brand); }
+.foot-docs svg { width: 13px; height: 13px; stroke-width: 1.5; transition: transform .2s; }
+.foot-docs:hover svg { transform: translateX(2px); }
 
 /* ---------- the maker's plate ----------
  * Clockmakers signed the backplate — the brass face only a repairer sees once
@@ -199,7 +238,7 @@ main { max-width: 1180px; margin: 0 auto; padding: 20px; display: grid; gap: 18p
     var(--panel);
   transition: color .2s, border-color .2s;
 }
-.ss-plate__link:hover { color: var(--text); border-color: var(--accent); }
+.ss-plate__link:hover { color: var(--text); border-color: var(--brand); }
 
 .ss-plate__logo { flex: 0 0 auto; width: 46px; height: auto; opacity: .85;
   transition: opacity .2s; }
@@ -209,9 +248,9 @@ main { max-width: 1180px; margin: 0 auto; padding: 20px; display: grid; gap: 18p
   font-family: var(--mono); font-size: 12px; font-weight: 600;
   text-transform: uppercase; letter-spacing: .14em; }
 .ss-plate__body { display: block; font-size: 13px; line-height: 1.55; max-width: 62ch; }
-.ss-plate__name { color: var(--accent); }
+.ss-plate__name { color: var(--brand); }
 .ss-plate__cta { display: inline-flex; align-items: center; gap: 5px; margin-top: 8px;
-  font-size: 12px; color: var(--accent); }
+  font-size: 12px; color: var(--brand); }
 .ss-plate__cta svg { width: 14px; height: 14px; transition: transform .2s; }
 .ss-plate__link:hover .ss-plate__cta svg { transform: translateX(2px); }