fix: suppression de tous les LIMIT hardcodés dans les requêtes SQL

Supprime les LIMIT arbitraires qui tronquaient silencieusement les résultats:

- analysis.py   : LIMIT 5, 10, 100, 500 (pays ASN, top pays, UAs)
- variability.py: LIMIT 10, 20 (JA4s, pays, ASNs, hosts, UAs)
- fingerprints.py: LIMIT 10, 20, 100 (IPs, UAs, JA4 spoofing)
- entities.py   : LIMIT 100 (IPs associées)
- tcp_spoofing.py: LIMIT 10, 12, 15 (distributions TTL/MSS/window)
- heatmap.py    : LIMIT 15
- search.py     : LIMIT 5 (suggestions de recherche)

Conservés: LIMIT 1 (lookup d'un seul enregistrement) et
LIMIT %(limit)s / OFFSET (pagination contrôlée par le frontend).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/routes/tcp_spoofing.py

@@ -47,7 +47,7 @@ async def get_tcp_spoofing_overview():
         SELECT tcp_ttl_raw AS ttl, count() AS cnt, uniq(src_ip) AS ips
         FROM mabase_prod.agg_host_ip_ja4_1h
         WHERE window_start >= now() - INTERVAL 24 HOUR AND tcp_ttl_raw > 0
-        GROUP BY ttl ORDER BY cnt DESC LIMIT 15
+        GROUP BY ttl ORDER BY cnt DESC
         """
         ttl_res = db.query(ttl_sql)
 
@@ -56,7 +56,7 @@ async def get_tcp_spoofing_overview():
         SELECT tcp_mss_raw AS mss, count() AS cnt, uniq(src_ip) AS ips
         FROM mabase_prod.agg_host_ip_ja4_1h
         WHERE window_start >= now() - INTERVAL 24 HOUR AND tcp_mss_raw > 0
-        GROUP BY mss ORDER BY cnt DESC LIMIT 12
+        GROUP BY mss ORDER BY cnt DESC
         """
         mss_res = db.query(mss_sql)
 
@@ -65,7 +65,7 @@ async def get_tcp_spoofing_overview():
         SELECT tcp_win_raw AS win, count() AS cnt
         FROM mabase_prod.agg_host_ip_ja4_1h
         WHERE window_start >= now() - INTERVAL 24 HOUR AND tcp_ttl_raw > 0
-        GROUP BY win ORDER BY cnt DESC LIMIT 10
+        GROUP BY win ORDER BY cnt DESC
         """
         win_res = db.query(win_sql)