feat(storage): add warn data persistence layer

Implement server-side storage module for managing player warnings.

Provides functionality to:
- Load and save warnings from/to JSON file
- Retrieve warnings for a specific player
- Add new warnings with issuer information
- Remove individual warnings by index
- Clear all warnings for a player

Warnings are stored with issuer, issuerid, timestamp, reason, and comment.

lua/bladw_warn/server/sv_storage.lua

@@ -0,0 +1,47 @@
+BladW = BladW or {}
+BladW.Warn = BladW.Warn or {}
+
+-- stockage des warns : { [steamid64] = { { issuer, issuerid, time, reason, comment }, ... } }
+local DIR  = "bladw_warn"
+local FILE = "bladw_warn/warns.json"
+
+BladW.Warn.Data = BladW.Warn.Data or {}
+
+function BladW.Warn.Save()
+    file.CreateDir(DIR)
+    file.Write(FILE, util.TableToJSON(BladW.Warn.Data))
+end
+
+function BladW.Warn.Load()
+    local raw = file.Read(FILE, "DATA")
+    BladW.Warn.Data = (raw and util.JSONToTable(raw)) or {}
+end
+
+function BladW.Warn.Get(sid)
+    return BladW.Warn.Data[sid] or {}
+end
+
+function BladW.Warn.AddWarn(sid, entry)
+    if not sid or sid == "" then return end
+    BladW.Warn.Data[sid] = BladW.Warn.Data[sid] or {}
+    table.insert(BladW.Warn.Data[sid], entry)
+    BladW.Warn.Save()
+end
+
+function BladW.Warn.RemoveWarn(sid, index)
+    local t = BladW.Warn.Data[sid]
+    if t and t[index] then
+        table.remove(t, index)
+        if #t == 0 then BladW.Warn.Data[sid] = nil end
+        BladW.Warn.Save()
+        return true
+    end
+    return false
+end
+
+function BladW.Warn.ClearWarns(sid)
+    BladW.Warn.Data[sid] = nil
+    BladW.Warn.Save()
+end
+
+BladW.Warn.Load()