Fix device ID parsing regression in Mithril 2.3.8

Device IDs containing literal % characters (e.g., "202BC1-CODA%2D5519-000000")
are double-encoded in URLs. Mithril 2.3.8 incorrectly double-decodes route
parameters, corrupting device IDs with special characters.

Workaround: Extract device ID directly from window.location.hash and decode
once to get the correct value.

See: https://github.com/MithrilJS/mithril.js/issues/3064

ui/device-page.ts

@@ -3,6 +3,29 @@ import { m } from "./components.ts";
 import config from "./config.ts";
 import * as store from "./store.ts";
 
+// Workaround for Mithril 2.3.8 regression
+// https://github.com/MithrilJS/mithril.js/issues/3064
+function getPathParamFromHash(hash: string, prefix: string): string | null {
+  if (!hash.startsWith(prefix)) return null;
+
+  const pathWithQuery = hash.slice(prefix.length);
+
+  // Stop at query string or hash fragment (mirrors Mithril's parsePathname)
+  const queryIdx = pathWithQuery.indexOf("?");
+  const hashIdx = pathWithQuery.indexOf("#");
+  let pathEnd = pathWithQuery.length;
+  if (queryIdx >= 0) pathEnd = Math.min(pathEnd, queryIdx);
+  if (hashIdx >= 0) pathEnd = Math.min(pathEnd, hashIdx);
+
+  const rawPath = pathWithQuery.slice(0, pathEnd);
+
+  // Normalize: collapse slashes, remove trailing slash (matches Mithril)
+  const normalizedPath = rawPath.replace(/\/{2,}/g, "/").replace(/\/$/, "");
+
+  // Decode once (Mithril already decoded with decodeURIComponentSafe)
+  return decodeURIComponent(normalizedPath);
+}
+
 export function init(
   args: Record<string, unknown>,
 ): Promise<Record<string, unknown>> {
@@ -12,9 +35,13 @@ export function init(
     );
   }
 
+  const deviceId =
+    getPathParamFromHash(window.location.hash, "#!/devices/") ??
+    (args.id as string);
+
   return Promise.resolve({
-    deviceId: args.id,
-    deviceFilter: ["=", ["PARAM", "DeviceID.ID"], args.id],
+    deviceId: deviceId,
+    deviceFilter: ["=", ["PARAM", "DeviceID.ID"], deviceId],
   });
 }