feat(learner): zone-scoped export; 200k entry cap; SmoothReset after import

QuestieLearnerExport:
- Extract _Encode helper to consolidate serialize+deflate+encode
- Add ExportZone(serverKey, zoneId) to export only the learned data
  for a specific zone (NPCs/objects with spawns in that zone, plus
  their dropped items and related quests) for smaller, faster exports
- Cap ValidateImport at 200k entries to guard against pathological
  payloads that could stall the client during merge
- Call SmoothReset after MergeImport so newly imported spawns appear
  on the map without requiring /reload

QuestieOptionsDatabase:
- Refresh AceConfigRegistry after import so Database tab stats update
  immediately (previously required /reload or opening Options)
- Add Export Current Zone button tied to ExportZone()

Modules/Options/DatabaseTab/QuestieOptionsDatabase.lua

@@ -197,6 +197,12 @@ _OpenImportDialog = function()
         if ok then
             statusLabel:SetText("|cFF00FF00" .. msg .. "|r")
             importBtn:SetDisabled(true)
+            -- Refresh the Database tab so the live stats counts update immediately
+            -- (the map/minimap is already redrawn inside MergeImport via SmoothReset).
+            local AceConfigRegistry = LibStub("AceConfigRegistry-3.0", true)
+            if AceConfigRegistry and AceConfigRegistry.NotifyChange then
+                AceConfigRegistry:NotifyChange("Questie")
+            end
         else
             statusLabel:SetText("|cFFFF0000" .. msg .. "|r")
         end
@@ -411,6 +417,26 @@ function QuestieOptions.tabs.database:Initialize()
                 end,
             },
 
+            export_zone_btn = {
+                type  = "execute",
+                order = 3.25,
+                name  = function() return l10n("Export Current Zone") end,
+                desc  = function() return "Export only the learned data for the zone you are standing in (NPCs/objects in the zone, plus the items they drop and quests they give)." end,
+                func  = function()
+                    local Exp = GetExportModule()
+                    if not Exp then
+                        Questie:Print("|cFFFF0000QuestieLearnerExport module not loaded.|r")
+                        return
+                    end
+                    local str, statsOrErr = Exp:ExportZone()
+                    if not str then
+                        Questie:Print("|cFFFF0000Export failed: " .. tostring(statsOrErr) .. "|r")
+                    else
+                        _OpenExportDialog(str, statsOrErr)
+                    end
+                end,
+            },
+
             export_all_btn = {
                 type  = "execute",
                 order = 3.3,