Add buffer-aware reconnect urgency

- co_connect: aggressive reconnect when buffer >80%
- Buffer warning at 80%, overflow drop at 100%
- Frequent flush attempts to clear buffer
- Clear log messages for buffer state

package/src/client2server-unified.lua

@@ -104,8 +104,17 @@ function buffer.save()
 end
 
 function buffer.add(json_event)
+    -- Warn if buffer is getting full
+    if #buffer.events > cfg.max_buffer * 0.8 then
+        log_err("Buffer almost full: " .. #buffer.events .. "/" .. cfg.max_buffer)
+    end
+    
     table.insert(buffer.events, json_event)
-    if #buffer.events > cfg.max_buffer then table.remove(buffer.events, 1) end
+    if #buffer.events > cfg.max_buffer then
+        -- Buffer full - drop oldest to make room
+        table.remove(buffer.events, 1)
+        log_err("Buffer overflow: dropping oldest event")
+    end
     buffer.dirty = true
 end
 
@@ -380,6 +389,14 @@ local function co_connect()
     local max_delay = 300    -- Max 5 minutes
     
     while true do
+        -- Urgency based on buffer state
+        local buffer_fullness = #buffer.events / cfg.max_buffer
+        
+        if buffer_fullness > 0.8 then
+            log_err("Buffer critical at " .. string.format("%.0f%%", buffer_fullness * 100) .. " - aggressive reconnect")
+            retry_delay = 10  -- Aggressive when buffer filling
+        end
+        
         if not ws.connected then
             log_info("Connecting to " .. cfg.server_url .. "...")
             
@@ -396,7 +413,9 @@ local function co_connect()
                 retry_delay = math.min(retry_delay * 2, max_delay)
             end
         else
-            coroutine.yield(30)  -- Still connected, check every 30s
+            -- Even when connected, periodically flush to clear buffer buildup
+            buffer.flush(function(d) return ws.send(d) end)
+            coroutine.yield(30)
         end
     end
 end