v2.7.1 — image edit improvements, search config, bug fixes

image_edit:
- speech_bubble operation with Korean font, rounded rect, tail
- sketch quality: CLAHE pre-processing for better line contrast
- output filename with timestamp to prevent overwrites
- anime/painting stylize timeout 30s→600s (AnimeGANv2 model download)
- remove_bg PNG output fix

server-v2.ts:
- resolveToolImageContent: embed edited image as base64 in tool results
  so vision models can see the output (3 execution paths covered)
- _activeModelName: fix vision support detection for Ollama-hosted models
  (kimi/gemini run via Ollama — provider='ollama' was masking vision capability)
- Synthetic tool call ID generation to prevent Gemini function_response empty name error
- image_edit path hint format changed to English to prevent Gemini hallucination
- userRequestedImageEdit: expanded keyword list (풍선, 달아, 붙여 등)
- image_read OCR failure returns success:true with visual description hint
- TOOL_BLOCKS photo: image_edit workflow documentation updated

web-ui/index.html:
- renderFileDownloads: skip download buttons for image file extensions

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web-ui/index.html

@@ -4604,10 +4604,12 @@ function renderFileDownloads(steps, processEntries) {
     }
   }
 
+  const _imgExts = /\.(jpg|jpeg|png|gif|webp|heic|heif|bmp|svg|avif|tiff|tif)(\?|$)/i;
   for (const rawUrl of allUrls) {
     if (seenUrls.has(rawUrl)) continue;
     seenUrls.add(rawUrl);
     const decoded = (() => { try { return decodeURIComponent(rawUrl); } catch { return rawUrl; } })();
+    if (_imgExts.test(decoded)) continue; // images shown inline, no download button needed
     const filename = decoded.split('/').pop() || 'download';
     const isPptx = decoded.toLowerCase().indexOf('.pptx') !== -1;
     if (isPptx) {