feat: add "Articles sans date" category for articles without publication date

Articles where neither the scraper nor the LLM could extract a date
are now placed in a separate "Articles sans date" section instead of
their classified category. This makes undated articles visible without
mixing them with properly dated content.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/src/services/synthesis.rs

@@ -522,6 +522,24 @@ pub async fn run_generation_inner(
                                 }
                             }
 
+                            let llm_date = class_response.get("date").and_then(|d| d.as_str()).filter(|s| !s.is_empty()).map(|s| s.to_string());
+
+                            // Articles without any date go to "Articles sans date" category
+                            if llm_date.is_none() {
+                                let llm_title = class_response.get("title").and_then(|t| t.as_str()).unwrap_or(&page_title).to_string();
+                                let llm_summary = class_response.get("summary").and_then(|s| s.as_str()).unwrap_or("").to_string();
+                                article_scraped.entry("category_no_date".to_string()).or_default().push(NewsItem {
+                                    title: llm_title,
+                                    url: final_url.clone(),
+                                    summary: llm_summary,
+                                    date: None,
+                                });
+
+                                let source_domain = extract_domain(&source_url).unwrap_or_default();
+                                *source_counts.entry(source_domain).or_insert(0) += 1;
+                                continue;
+                            }
+
                             let Some((final_cat_key, final_cat_name, llm_title, llm_summary)) = assign_category(
                                 &class_response, &page_title, &user_categories, &classification_categories,
                                 &filled_counts, settings.max_items_per_category as usize,
@@ -529,7 +547,6 @@ pub async fn run_generation_inner(
                                 continue;
                             };
 
-                            let llm_date = class_response.get("date").and_then(|d| d.as_str()).filter(|s| !s.is_empty()).map(|s| s.to_string());
                             article_scraped.entry(final_cat_key).or_default().push(NewsItem {
                                 title: llm_title,
                                 url: final_url.clone(),
@@ -747,6 +764,25 @@ pub async fn run_generation_inner(
                                 }
                             }
 
+                            let llm_date = class_response.get("date").and_then(|d| d.as_str()).filter(|s| !s.is_empty()).map(|s| s.to_string());
+
+                            // Articles without any date go to "Articles sans date" category
+                            if llm_date.is_none() {
+                                let llm_title = class_response.get("title").and_then(|t| t.as_str()).unwrap_or(&page_title).to_string();
+                                let llm_summary = class_response.get("summary").and_then(|s| s.as_str()).unwrap_or("").to_string();
+                                article_scraped.entry("category_no_date".to_string()).or_default().push(NewsItem {
+                                    title: llm_title,
+                                    url: final_url.clone(),
+                                    summary: llm_summary,
+                                    date: None,
+                                });
+
+                                if let Some(domain) = extract_domain(&final_url) {
+                                    *source_counts.entry(domain).or_insert(0) += 1;
+                                }
+                                continue;
+                            }
+
                             let Some((final_cat_key, final_cat_name, llm_title, llm_summary)) = assign_category(
                                 &class_response, &page_title, &user_categories, &classification_categories,
                                 &filled_counts, settings.max_items_per_category as usize,
@@ -754,7 +790,6 @@ pub async fn run_generation_inner(
                                 continue;
                             };
 
-                            let llm_date = class_response.get("date").and_then(|d| d.as_str()).filter(|s| !s.is_empty()).map(|s| s.to_string());
                             article_scraped.entry(final_cat_key).or_default().push(NewsItem {
                                 title: llm_title,
                                 url: final_url.clone(),
@@ -885,6 +920,11 @@ pub async fn run_generation_inner(
             final_sections.push(NewsSection { title: "Divers".to_string(), items: autre_items.clone() });
         }
     }
+    if let Some(no_date_items) = article_scraped.get("category_no_date") {
+        if !no_date_items.is_empty() {
+            final_sections.push(NewsSection { title: "Articles sans date".to_string(), items: no_date_items.clone() });
+        }
+    }
 
     let sections_json = serde_json::to_value(&final_sections).map_err(|e| AppError::Internal(anyhow::anyhow!("Failed to serialize: {}", e)))?;
     let sections_json = sanitize_json_null_bytes(sections_json);