feat: photo quality improvements

- webcam capture resolution/quality configurable in admin settings (defaults 640x480 / 0.92)
- enhance photo modal in journal: original vs preview with sliders (brightness, contrast, saturation, sharpen) and auto-levels button
- new endpoint PUT /api/entries/:id/photo/enhance replaces photo, cleans old file and thumb
- sharper HEIC conversion (0.92) and webp thumbnails (85)
- worker: fail explicitly on empty AI response

public/js/index.js

@@ -21,6 +21,9 @@ const sentText = document.getElementById('sentText');
 const sentTimer = document.getElementById('sentTimer');
 const SENT_KEY = 'whatido_entry_sent_at';
 let entryCooldownMin = 30;
+let captureWidth = 640;
+let captureHeight = 480;
+let captureQuality = 0.92;
 let sentTimerId = null;
 
 function unlockForm() {
@@ -156,6 +159,12 @@ if (params.get('nameInput')) {
     if (f.footer_right) document.getElementById('footerRight').textContent = f.footer_right;
     const c = parseInt(f.spam_interval_min, 10);
     if (Number.isFinite(c) && c >= 1) entryCooldownMin = c;
+    const w = parseInt(f.photo_capture_width, 10);
+    const h = parseInt(f.photo_capture_height, 10);
+    if (Number.isFinite(w) && w >= 160 && w <= 4096) captureWidth = w;
+    if (Number.isFinite(h) && h >= 120 && h <= 4096) captureHeight = h;
+    const q = parseFloat(f.photo_capture_quality);
+    if (Number.isFinite(q) && q >= 0.5 && q <= 1) captureQuality = q;
   } catch (e) { /* ignore */ }
   checkPreviousSend();
 })();
@@ -175,7 +184,7 @@ function removePhoto() {
 
 async function openCam() {
   try {
-    stream = await navigator.mediaDevices.getUserMedia({ video: { facingMode: 'user', width: { ideal: 640 }, height: { ideal: 480 } } });
+    stream = await navigator.mediaDevices.getUserMedia({ video: { facingMode: 'user', width: { ideal: captureWidth }, height: { ideal: captureHeight } } });
     camVideo.srcObject = stream;
     camModal.classList.add('open');
   } catch (e) {
@@ -199,7 +208,7 @@ function capture() {
     capturedBlob = blob;
     showPreview(URL.createObjectURL(blob));
     closeCam();
-  }, 'image/jpeg', 0.85);
+  }, 'image/jpeg', captureQuality);
 }
 
 form.addEventListener('submit', async (e) => {