HNS+UI: 4 nova endpointa + multi-sport schema (M2M kategorije + player_stats)

Endpoints:
- GET /api/v2/enrich-sources — sport→source mapping
- GET /api/v2/klubovi/priority-sort — financirani/godišnjak prvi
- GET /api/v2/clan/{id}/kategorije — many-to-many kategorije
- GET /api/v2/clan/{id}/full — kompletna slika (profil+kategorije+sezone+utakmice+stats)
- POST /api/v2/export/klubovi — XLSX export selektiranih

Schema:
- pgz_sport.clan_kategorije (M2M: igrač u juniorskoj+seniorskoj)
- pgz_sport.player_stats (multi-sport: nogomet/košarka/rukomet/odbojka/vaterpolo)
- pgz_sport.klub_roster (multi-source)
- pgz_sport.enrichment_sources (sport→izvor)
- View: v_pgz_priority_klubovi (financiran || u_godisnjaku)
- View: v_klubovi_priority_sort (priority sort)

Sport harvesters scaffold:
- scripts/sport_harvesters/__base.py (SportHarvester class)
- hks_basketball.py, hrs_handball.py, hos_volleyball.py, hvs_waterpolo.py

scripts/sport_harvesters/hos_volleyball.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+"""HOS volleyball harvester."""
+import sys
+sys.path.insert(0, '/opt/pgz-sport/scripts/sport_harvesters')
+from __base import SportHarvester
+
+class HOSHarvester(SportHarvester):
+    SPORT = 'odbojka'
+    SOURCE = 'hos'
+    
+    def scrape_klub(self, page, klub):
+        # HOS-CVF.hr search
+        self.log(f"  🏐 Klub {klub['id']} {klub['naziv']}")
+        try:
+            page.goto("https://hos-cvf.hr/", wait_until="domcontentloaded", timeout=20000)
+            self.log(f"    [discovery mode] HOS site loaded")
+        except Exception as e:
+            self.log(f"    ❌ {e}")
+
+if __name__ == '__main__':
+    HOSHarvester().run(limit=int(sys.argv[1]) if len(sys.argv) > 1 else 50)