Preserve extension quality with original segments and reliable refinement

server/utils/extendChain.ts

@@ -125,7 +125,7 @@ export async function beginExtendFromClip(params: {
   const height = source.height || 768
   const clipName = String(params.name || '').trim() || nextFamilyPartName(params.ownerKey, source)
   const refineExtensionFrame = parseRefineExtensionFrame(params.refineExtensionFrame, true)
-  const saveLosslessAnchor = parseSaveLosslessAnchor(params.saveLosslessAnchor, false)
+  const saveLosslessAnchor = parseSaveLosslessAnchor(params.saveLosslessAnchor, true)
   const refinementDenoise = clampRefinementDenoise(params.refinementDenoise, REFINEMENT_DENOISE_DEFAULT)
 
   const job = createJob()
@@ -252,7 +252,6 @@ async function runExtend(
     })
   })
 
-  const done = watchComfyJob(job)
   if (params.refineExtensionFrame !== false) {
     emitJob(job, {
       type: 'status',
@@ -268,19 +267,18 @@ async function runExtend(
         seed: params.seed,
         clientId: job.clientId,
         jobId: job.id,
+        onQueued: (promptId) => { job.promptId = promptId },
         onStatus: (message) => emitJob(job, { type: 'status', message, progress: 4 })
       })
       writeFileSync(params.framePath, frame)
     } catch (error) {
-      const detail = error instanceof Error ? error.message : String(error)
-      emitJob(job, {
-        type: 'status',
-        message: `Frame refine skipped (${detail}). Using source frame.`,
-        progress: 4
-      })
+      throw new Error(`Extension frame refinement failed: ${error instanceof Error ? error.message : String(error)}. Retry after fixing refinement, or explicitly turn it off.`)
     }
   }
 
+  if (job.status === 'cancelled' || job.status === 'error') throw new Error('Extension stopped before video generation')
+  job.promptId = undefined
+  const done = watchComfyJob(job)
   job.status = 'uploading'
   emitJob(job, { type: 'status', message: 'Uploading last frame to ComfyUI...', progress: 5 })
   const uploaded = await uploadImage({ filename: 'last_frame.png', data: frame, type: 'image/png' }, job.id)
@@ -310,7 +308,7 @@ async function runExtend(
     workflow: job.library?.workflow,
     duration: job.library?.duration,
     loraStack: params.loraStack || job.library?.loraStack || params.loraName || job.library?.loraName,
-    saveLosslessAnchor: params.saveLosslessAnchor === true || job.library?.saveLosslessAnchor === true
+    saveLosslessAnchor: (params.saveLosslessAnchor ?? job.library?.saveLosslessAnchor) !== false
   })
 
   const queued = await queuePrompt(graph, job.clientId)