fix: simplify path encoding per review — inline utils, use single key scheme

Address PR review comments:
- Remove pathUtils.ts and move sanitize/encodePath directly into utils.ts
- Simplify dual-key approach to single key using encodePath for map keys
- Remove backward-compat logic (not needed per reviewer)
- Update tests to match simplified approach

server/lib/traefik/utils.ts

@@ -1,7 +1,37 @@
 import logger from "@server/logger";
 
-// Re-export pure functions from dependency-free module
-export { sanitize, encodePath } from "./pathUtils";
+export function sanitize(input: string | null | undefined): string | undefined {
+    if (!input) return undefined;
+    // clean any non alphanumeric characters from the input and replace with dashes
+    // the input cant be too long either, so limit to 50 characters
+    if (input.length > 50) {
+        input = input.substring(0, 50);
+    }
+    return input
+        .replace(/[^a-zA-Z0-9-]/g, "-")
+        .replace(/-+/g, "-")
+        .replace(/^-|-$/g, "");
+}
+
+/**
+ * Encode a URL path into a collision-free alphanumeric string suitable for use
+ * in Traefik map keys.
+ *
+ * Unlike sanitize(), this preserves uniqueness by encoding each non-alphanumeric
+ * character as its hex code. Different paths always produce different outputs.
+ *
+ *   encodePath("/api")  => "2fapi"
+ *   encodePath("/a/b")  => "2fa2fb"
+ *   encodePath("/a-b")  => "2fa2db"   (different from /a/b)
+ *   encodePath("/")     => "2f"
+ *   encodePath(null)    => ""
+ */
+export function encodePath(path: string | null | undefined): string {
+    if (!path) return "";
+    return path.replace(/[^a-zA-Z0-9]/g, (ch) => {
+        return ch.charCodeAt(0).toString(16);
+    });
+}
 
 export function validatePathRewriteConfig(
     path: string | null,