Make dedupe stricter to avoid wrongly archiving distinct placeholder-facility ads

The job/talent duplicate-detector compared only the first 100–120 chars of the normalized
description. Since ~82% of jobs share the «نامشخص» placeholder facility, two genuinely different
ads that merely open the same way could collapse — wrongly archiving a valid listing (→ a 410 like
/Jobs/Details/7032). Compare a 400-char slice instead, so only near-identical full texts dedupe;
true reposts/fan-out (identical text) are still caught.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/JobsMedical.Web/Services/Scraping/IngestionService.cs

@@ -288,7 +288,7 @@ public class IngestionService
             var core = NormalizeFa(Regex.Replace(desc ?? "",
                 @"[0-9۰-۹]+|روز پیش|ساعت پیش|هفته پیش|دقیقه پیش|دیروز|پریروز", " ")).Trim();
             if (core.Length < 15) return null;                              // too little to call it a dup safely
-            return $"t:{roleId}:{cityId}:{(core.Length > 100 ? core[..100] : core)}";
+            return $"t:{roleId}:{cityId}:{(core.Length > 400 ? core[..400] : core)}";
         }
 
         var toRemove = rows
@@ -497,7 +497,9 @@ public class IngestionService
             var core = NormalizeFa(Regex.Replace(desc ?? "",
                 @"[0-9۰-۹]+|روز پیش|ساعت پیش|هفته پیش|دقیقه پیش|دیروز|پریروز", " ")).Trim();
             if (core.Length < 15) return null;                      // too little to call it a dup safely
-            return $"j:{facId}:{(core.Length > 120 ? core[..120] : core)}";
+            // Compare a LONG slice (not 120) — most jobs share the «نامشخص» facility, so a short
+            // prefix could collapse two different placeholder ads that merely open the same way.
+            return $"j:{facId}:{(core.Length > 400 ? core[..400] : core)}";
         }
 
         // Keep one per group — prefer a non-«پزشک عمومی» role (the fan-out's GP copy is the usual