Update scan interval and remove redundant cache refresh logic in main loop

inventoryManager.lua

@@ -5,7 +5,7 @@ local DROPPER_NAME  = "minecraft:dropper_9"
 local BARREL_NAME   = "minecraft:barrel_0"
 local POLL_INTERVAL = 2    -- seconds between barrel checks
 local MONITOR_SIDE  = "left"
-local SCAN_INTERVAL = 3    -- seconds between background scans
+local SCAN_INTERVAL = 120  -- seconds between full background scans
 local SMELT_INTERVAL = 3   -- seconds between furnace checks
 local SMELT_RESERVE  = 64  -- keep at least 1 stack of each raw material
 local CACHE_FILE     = ".inventory_cache"  -- persistent cache file
@@ -1810,12 +1810,6 @@ local function main()
                 pcall(refreshFurnaceStatus)
                 needsRedraw = true
                 smelterNeedsRedraw = true
-                -- If work was done, scan sooner to update cache
-                if ok and didWork then
-                    pcall(refreshCache)
-                    needsRedraw = true
-                    smelterNeedsRedraw = true
-                end
                 sleep(SMELT_INTERVAL)
             end
         end,