Expand test coverage across server, agent, and web; fix bugs found during audit.

Adds hundreds of unit/integration/e2e tests, fixes WS bcrypt auth, config merge, fleet analytics, agent schedule/log tail, and documents stale PROBLEMS items. Updates PROBLEMS.md, README, and test scripts; ignores local spread-kits and coverage dirs.

server/internal/api/config_handler.go

@@ -4,13 +4,10 @@ import (
 	"encoding/json"
 	"net/http"
 	"strings"
-
-	"crypto-miner-server/internal/db"
 )
 
 // ConfigHandler handles GET/PUT for server configuration settings
 type ConfigHandler struct {
-	db     *db.Database
 	config ConfigProvider
 }
 
@@ -20,11 +17,8 @@ type ConfigProvider interface {
 	UpdateConfigFromJSON(data json.RawMessage) error
 }
 
-func NewConfigHandler(database *db.Database, cp ConfigProvider) *ConfigHandler {
-	return &ConfigHandler{
-		db:     database,
-		config: cp,
-	}
+func NewConfigHandler(cp ConfigProvider) *ConfigHandler {
+	return &ConfigHandler{config: cp}
 }
 
 func (h *ConfigHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {