Add configurable formats and lazy decoders, v0.7.1

app/static/index.html

@@ -16,7 +16,7 @@
         <div class="brand-mark" aria-hidden="true">◫</div>
         <div>
           <h1 id="app-name">Photo Date Editor</h1>
-          <p id="app-subtitle">Local folder · in-place JPG, PNG, TIFF, HEIF and DNG metadata</p>
+          <p id="app-subtitle">Loading enabled photo formats…</p>
         </div>
       </div>
       <div class="top-actions">
@@ -74,7 +74,7 @@
             </select>
           </div>
           <div id="file-list" class="file-list" aria-live="polite">
-            <div class="empty-list">Choose a folder containing JPG, PNG, TIFF, HEIC, HEIF, HIF, or DNG photos.</div>
+            <div class="empty-list">Choose a folder containing an enabled photo format.</div>
           </div>
         </section>