Fix multipart upload failure: raise body limit and fix catch syntax

Axum 0.7 defaults to a 2 MB body limit, which rejects typical phone photos
(often 5–15 MB). Added DefaultBodyLimit::max(50 MB) to accept large images.

Also changed `catch {}` to `catch (e) {}` in the sessionStorage IIFE; the
optional-catch-binding syntax (ES2019) is not supported by all mobile
WebViews, which would have prevented the script from loading entirely.

https://claude.ai/code/session_015myTTMs6yDsAGarATe5ePZ

src/main.rs

@@ -1,6 +1,6 @@
 use axum::{
     body::Body,
-    extract::{Multipart, Query, State},
+    extract::{DefaultBodyLimit, Multipart, Query, State},
     http::{header, StatusCode},
     response::{Html, Json, Response},
     routing::{get, post},
@@ -65,6 +65,7 @@ async fn main() {
         .route("/upload", post(upload))
         .route("/download", get(download))
         .route("/reset", post(reset_session))
+        .layer(DefaultBodyLimit::max(50 * 1024 * 1024)) // 50 MB – phone photos can be large
         .with_state(state);
 
     let addr = "0.0.0.0:3000";

templates/index.html

@@ -158,7 +158,7 @@
   <script>
     // Restore coords if iOS discarded the page while camera was open
     let gpsCoords = (() => {
-      try { return JSON.parse(sessionStorage.getItem('gpsCoords')); } catch { return null; }
+      try { return JSON.parse(sessionStorage.getItem('gpsCoords')); } catch (e) { return null; }
     })();
 
     function getLocation() {