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/analysis.py

@@ -141,7 +141,6 @@ async def analyze_ip_country(ip: str):
           AND detected_at >= now() - INTERVAL 24 HOUR
         GROUP BY country_code
         ORDER BY count DESC
-        LIMIT 10
         """
         
         asn_result = db.query(asn_countries_query, {"asn_number": asn_number})
@@ -190,7 +189,6 @@ async def analyze_country(days: int = Query(1, ge=1, le=30)):
           AND country_code != '' AND country_code IS NOT NULL
         GROUP BY country_code
         ORDER BY count DESC
-        LIMIT 10
         """
 
         top_result = db.query(top_query, {"days": days})
@@ -227,7 +225,6 @@ async def analyze_country(days: int = Query(1, ge=1, le=30)):
           AND country_code != '' AND country_code IS NOT NULL
         GROUP BY country_code
         ORDER BY count DESC
-        LIMIT 5
         """
         
         baseline_result = db.query(baseline_query)
@@ -309,7 +306,6 @@ async def analyze_ja4(ip: str):
           AND detected_at >= now() - INTERVAL 24 HOUR
         GROUP BY src_ip
         ORDER BY count DESC
-        LIMIT 100
         """
         
         subnets_result = db.query(subnets_query, {"ja4": ja4})
@@ -373,7 +369,6 @@ async def analyze_user_agents(ip: str):
           AND time >= now() - INTERVAL 24 HOUR
         GROUP BY ua
         ORDER BY count DESC
-        LIMIT 500
         """
         
         # Total réel des requêtes (pour les pourcentages corrects)