feat(odin): animated Odin brand mark (AI core orbiting business data)

A self-contained animated SVG mark in BOHA red: a 4-point AI spark (Odin) that
slow-rotates and breathes, a data node orbiting a faint ring (the assistant at
the centre of the business system). An "idle" and a "thinking" state (faster
orbit + red glow); honours prefers-reduced-motion. Used as the sidebar brand,
the empty-state hero, and the busy/thinking indicator.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/admin/components/odin/OdinMark.tsx

@@ -0,0 +1,117 @@
+import { keyframes, styled } from "@mui/material/styles";
+import Box from "@mui/material/Box";
+import { useReducedMotion } from "framer-motion";
+
+/**
+ * Odin's animated brand mark: an AI "spark" (Odin) with a data node orbiting a
+ * ring — the assistant at the centre of the business system, in BOHA red. The
+ * spark slow-rotates and breathes; the node orbits. In the "thinking" state
+ * everything speeds up and the tile glows. Honours prefers-reduced-motion.
+ *
+ * The animations live in a `styled("svg")` (not inline style): Emotion only
+ * injects the @keyframes rule when the keyframes object is used inside
+ * sx/css/styled, and the child selectors keep the SVG elements plain/typed.
+ */
+const breathe = keyframes`
+  0%, 100% { transform: scale(0.9); opacity: 0.9; }
+  50% { transform: scale(1.08); opacity: 1; }
+`;
+const spin = keyframes`
+  from { transform: rotate(0deg); }
+  to { transform: rotate(360deg); }
+`;
+// Reduce-motion safe: opacity only (no transforms / no travel).
+const glow = keyframes`
+  0%, 100% { opacity: 0.55; }
+  50% { opacity: 1; }
+`;
+
+const Glyph = styled("svg", {
+  shouldForwardProp: (p) => p !== "thinking" && p !== "reduce",
+})<{ thinking: boolean; reduce: boolean }>(({ thinking, reduce }) => ({
+  width: "70%",
+  height: "70%",
+  overflow: "visible",
+  display: "block",
+  ...(reduce
+    ? {
+        // Reduce-motion: keep a calm opacity glow (no spin/orbit/travel). The
+        // `!important` + class specificity intentionally overrides the app-wide
+        // reduced-motion reset in GlobalStyles for this one small mark, since an
+        // opacity pulse is accessibility-safe (it isn't vestibular motion).
+        "& .odin-spark": {
+          animation: `${glow} ${thinking ? "1.1s" : "3s"} ease-in-out infinite !important`,
+        },
+      }
+    : {
+        "& .odin-orbit": {
+          transformBox: "view-box",
+          transformOrigin: "12px 12px",
+          animation: `${spin} ${thinking ? "1.6s" : "5.5s"} linear infinite`,
+        },
+        "& .odin-spin": {
+          transformBox: "view-box",
+          transformOrigin: "12px 12px",
+          animation: `${spin} ${thinking ? "4s" : "11s"} linear infinite`,
+        },
+        "& .odin-spark": {
+          transformBox: "fill-box",
+          transformOrigin: "center",
+          animation: `${breathe} ${thinking ? "1s" : "2.8s"} ease-in-out infinite`,
+        },
+      }),
+}));
+
+export interface OdinMarkProps {
+  size?: number;
+  state?: "idle" | "thinking";
+}
+
+export default function OdinMark({ size = 28, state = "idle" }: OdinMarkProps) {
+  const reduce = !!useReducedMotion();
+  const thinking = state === "thinking";
+
+  return (
+    <Box
+      sx={(t) => ({
+        width: size,
+        height: size,
+        borderRadius: "32%",
+        flexShrink: 0,
+        display: "inline-flex",
+        alignItems: "center",
+        justifyContent: "center",
+        background: `linear-gradient(135deg, ${t.vars!.palette.primary.main}, ${t.vars!.palette.primary.dark})`,
+        boxShadow: thinking
+          ? `0 0 ${Math.round(size * 0.5)}px 0 rgba(${t.vars!.palette.primary.mainChannel} / 0.55)`
+          : "none",
+        transition: "box-shadow 0.3s ease",
+      })}
+    >
+      <Glyph viewBox="0 0 24 24" thinking={thinking} reduce={reduce}>
+        {/* orbit ring */}
+        <circle
+          cx="12"
+          cy="12"
+          r="9.2"
+          fill="none"
+          stroke="#fff"
+          strokeOpacity="0.28"
+          strokeWidth="1"
+        />
+        {/* orbiting data node */}
+        <g className="odin-orbit">
+          <circle cx="12" cy="2.8" r="1.4" fill="#fff" />
+        </g>
+        {/* spark — group slow-rotates, the star breathes about its own centre */}
+        <g className="odin-spin">
+          <path
+            className="odin-spark"
+            d="M12 4.5 C12.5 9, 13 9.5, 17.5 12 C13 14.5, 12.5 15, 12 19.5 C11.5 15, 11 14.5, 6.5 12 C11 9.5, 11.5 9, 12 4.5 Z"
+            fill="#fff"
+          />
+        </g>
+      </Glyph>
+    </Box>
+  );
+}