feat: add French/European/US date formats + remove "Articles sans date" category

Date parser now supports: 25/03/2026, 25-03-2026, March 25 2026,
25 mars 2026, 15 février 2026, and short month variants.

Articles without dates are no longer routed to a separate category —
they stay in their LLM-classified category with date shown as empty.
This prevents losing good articles in a catch-all section.

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

backend/src/services/scraper.rs

@@ -601,6 +601,35 @@ pub fn parse_date_string(s: &str) -> Option<DateTime<Utc>> {
         return Some(naive.and_utc());
     }
 
+    // Try European/French formats: "25/03/2026", "25-03-2026"
+    for fmt in &["%d/%m/%Y", "%d-%m-%Y"] {
+        if let Ok(naive) = NaiveDate::parse_from_str(s, fmt) {
+            return naive.and_hms_opt(0, 0, 0).map(|ndt| ndt.and_utc());
+        }
+    }
+
+    // Try US format: "03/25/2026", "March 25, 2026"
+    for fmt in &["%m/%d/%Y", "%B %d, %Y", "%b %d, %Y"] {
+        if let Ok(naive) = NaiveDate::parse_from_str(s, fmt) {
+            return naive.and_hms_opt(0, 0, 0).map(|ndt| ndt.and_utc());
+        }
+    }
+
+    // Try French format: "25 mars 2026", "25 mar 2026"
+    // chrono doesn't parse French month names natively, so we translate first
+    let lowered = s.to_lowercase();
+    let english = lowered
+        .replace("janvier", "January").replace("février", "February").replace("fevrier", "February")
+        .replace("mars", "March").replace("avril", "April").replace("mai", "May")
+        .replace("juin", "June").replace("juillet", "July").replace("août", "August").replace("aout", "August")
+        .replace("septembre", "September").replace("octobre", "October")
+        .replace("novembre", "November").replace("décembre", "December").replace("decembre", "December");
+    for fmt in &["%d %B %Y", "%d %b %Y"] {
+        if let Ok(naive) = NaiveDate::parse_from_str(&english, fmt) {
+            return naive.and_hms_opt(0, 0, 0).map(|ndt| ndt.and_utc());
+        }
+    }
+
     None
 }
 
@@ -1130,6 +1159,41 @@ mod tests {
         assert!(parse_date_string("").is_none());
     }
 
+    #[test]
+    fn test_parse_european_date_slash() {
+        let dt = parse_date_string("25/03/2026");
+        assert!(dt.is_some());
+        assert_eq!(dt.unwrap().format("%Y-%m-%d").to_string(), "2026-03-25");
+    }
+
+    #[test]
+    fn test_parse_european_date_dash() {
+        let dt = parse_date_string("25-03-2026");
+        assert!(dt.is_some());
+        assert_eq!(dt.unwrap().format("%Y-%m-%d").to_string(), "2026-03-25");
+    }
+
+    #[test]
+    fn test_parse_us_date_long_month() {
+        let dt = parse_date_string("March 25, 2026");
+        assert!(dt.is_some());
+        assert_eq!(dt.unwrap().format("%Y-%m-%d").to_string(), "2026-03-25");
+    }
+
+    #[test]
+    fn test_parse_french_date() {
+        let dt = parse_date_string("25 mars 2026");
+        assert!(dt.is_some());
+        assert_eq!(dt.unwrap().format("%Y-%m-%d").to_string(), "2026-03-25");
+    }
+
+    #[test]
+    fn test_parse_french_date_accent() {
+        let dt = parse_date_string("15 février 2026");
+        assert!(dt.is_some());
+        assert_eq!(dt.unwrap().format("%Y-%m-%d").to_string(), "2026-02-15");
+    }
+
     // ── Scheme Validation ───────────────────────────────────────────
 
     #[test]

backend/src/services/synthesis/mod.rs

@@ -576,11 +576,6 @@ 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);
@@ -789,23 +784,6 @@ async fn scrape_and_classify_batch(
                 .and_then(extract_domain)
                 .or_else(|| extract_domain(&final_url));
 
-            // 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) = count_domain {
-                    *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, ctx.user_categories, ctx.classification_categories,
                 filled_counts, ctx.max_items_per_category,