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/search.py

@@ -32,7 +32,6 @@ async def quick_search(q: str = Query(..., min_length=1, max_length=100)):
           AND detected_at >= now() - INTERVAL 24 HOUR
         GROUP BY clean_ip
         ORDER BY hits DESC
-        LIMIT 5
         """,
         {"p": pattern},
     )
@@ -60,7 +59,6 @@ async def quick_search(q: str = Query(..., min_length=1, max_length=100)):
           AND detected_at >= now() - INTERVAL 24 HOUR
         GROUP BY ja4
         ORDER BY hits DESC
-        LIMIT 5
         """,
         {"p": pattern},
     )
@@ -86,7 +84,6 @@ async def quick_search(q: str = Query(..., min_length=1, max_length=100)):
           AND detected_at >= now() - INTERVAL 24 HOUR
         GROUP BY host
         ORDER BY hits DESC
-        LIMIT 5
         """,
         {"p": pattern},
     )
@@ -113,7 +110,6 @@ async def quick_search(q: str = Query(..., min_length=1, max_length=100)):
           AND detected_at >= now() - INTERVAL 24 HOUR
         GROUP BY asn_org, asn_number
         ORDER BY hits DESC
-        LIMIT 5
         """,
         {"p": pattern},
     )