Stream-process listings as IDs arrive via asyncio.Queue

Replace the sequential fetch-all-then-process pipeline with a streaming
architecture where listing processing starts as soon as IDs become
available from each subquery. A producer task fetches pages and enqueues
new IDs (filtered inline against DB), while 20 consumer workers process
listings concurrently from the queue.

- Add ListingRepository.get_listing_ids() for fast ID-only projection
- Refactor listing_tasks.py: remove get_ids_to_process/dump_listings_and_monitor,
  replace with unified producer/worker/monitor pipeline
- Apply same pattern to CLI path in listing_fetcher.py
- Remove 'filtering' phase from frontend, show combined fetch+process metrics
- Add fetching_done flag to TaskResult for phase transition tracking

crawler/frontend/src/components/TaskIndicator.tsx

@@ -180,7 +180,6 @@ export function TaskIndicator({ taskID, onTaskCancelled }: TaskIndicatorProps) {
                 splitting: 'Splitting',
                 splitting_complete: 'Split done',
                 fetching: 'Fetching',
-                filtering: 'Filtering',
             };
             return phaseLabels[taskResult.phase] ?? `${Math.round(progressPercentage)}%`;
         }

crawler/frontend/src/components/TaskProgressDrawer.tsx

@@ -23,9 +23,8 @@ interface TaskProgressDrawerProps {
 
 const PHASES: { key: TaskPhase; label: string }[] = [
     { key: 'splitting', label: 'Splitting queries' },
-    { key: 'fetching', label: 'Fetching listings' },
-    { key: 'filtering', label: 'Filtering results' },
-    { key: 'processing', label: 'Processing listings' },
+    { key: 'fetching', label: 'Fetching & processing' },
+    { key: 'processing', label: 'Processing remaining' },
 ];
 
 function getPhaseIndex(phase: TaskPhase | undefined): number {
@@ -175,7 +174,7 @@ function PhaseDetails({ result }: { result: TaskResult }) {
         return (
             <div className="rounded-md border p-3 space-y-1">
                 <p className="text-xs font-medium text-muted-foreground uppercase tracking-wide mb-2">
-                    Fetching
+                    {result.fetching_done ? 'Fetching complete' : 'Fetching & processing'}
                 </p>
                 <CounterRow
                     label="Subqueries completed"
@@ -184,19 +183,24 @@ function PhaseDetails({ result }: { result: TaskResult }) {
                 />
                 <CounterRow label="IDs collected" value={result.ids_collected} />
                 <CounterRow label="Pages fetched" value={result.pages_fetched} />
-            </div>
-        );
-    }
-
-    if (phase === 'filtering') {
-        return (
-            <div className="rounded-md border p-3 space-y-1">
-                <p className="text-xs font-medium text-muted-foreground uppercase tracking-wide mb-2">
-                    Filtering
-                </p>
-                <CounterRow label="Total from API" value={result.total_found} />
-                <CounterRow label="Already in DB" value={result.existing_in_db} />
-                <CounterRow label="New to process" value={result.new_listings} />
+                {(result.details_fetched !== undefined && result.details_fetched > 0) && (
+                    <>
+                        <div className="border-t my-2" />
+                        <CounterRow
+                            label="Details fetched"
+                            value={result.details_fetched}
+                            total={result.total}
+                        />
+                        <CounterRow label="Images downloaded" value={result.images_downloaded} />
+                        <CounterRow label="OCR completed" value={result.ocr_completed} />
+                        {(result.failed ?? 0) > 0 && (
+                            <div className="flex justify-between text-sm">
+                                <span className="text-red-500">Failed</span>
+                                <span className="font-mono tabular-nums text-red-500">{result.failed}</span>
+                            </div>
+                        )}
+                    </>
+                )}
             </div>
         );
     }
@@ -306,7 +310,7 @@ export function TaskProgressDrawer({
 
                     {taskResult && <PhaseDetails result={taskResult} />}
 
-                    {taskResult && taskResult.phase === 'processing' && (
+                    {taskResult && (taskResult.phase === 'processing' || taskResult.phase === 'fetching') && (taskResult.total ?? 0) > 0 && (
                         <div className="space-y-1">
                             <div className="w-full h-2 bg-primary/20 rounded-full overflow-hidden">
                                 <div

crawler/frontend/src/types/index.ts

@@ -52,7 +52,7 @@ export interface TaskStatusResponse {
   message?: string;
 }
 
-export type TaskPhase = 'splitting' | 'splitting_complete' | 'fetching' | 'filtering' | 'processing' | 'completed';
+export type TaskPhase = 'splitting' | 'splitting_complete' | 'fetching' | 'processing' | 'completed';
 
 export interface TaskResult {
   progress: number;
@@ -69,10 +69,7 @@ export interface TaskResult {
   subqueries_completed?: number;
   ids_collected?: number;
   pages_fetched?: number;
-  // Filtering phase
-  total_found?: number;
-  existing_in_db?: number;
-  new_listings?: number;
+  fetching_done?: boolean;
   // Processing phase
   details_fetched?: number;
   images_downloaded?: number;