feat: add SQLite support, setup wizard enhancements, and live dashboard

Add zero-dependency SQLite mode so users can run Erupe without
PostgreSQL. A transparent db.DB wrapper auto-translates PostgreSQL
SQL ($N placeholders, now(), ::casts, ILIKE, public. prefix,
TRUNCATE) for SQLite at runtime — all 28 repo files use the wrapper
with no per-query changes needed.

Setup wizard gains two new steps: quest file detection with download
link, and gameplay presets (solo/small/community/rebalanced). The API
server gets a /dashboard endpoint with auto-refreshing stats.

CI release workflow now builds and pushes Docker images to GHCR
alongside binary artifacts on tag push.

Key changes:
- common/db: DB/Tx wrapper with 6 SQL translation rules
- server/migrations/sqlite: full SQLite schema (0001-0005)
- config: Database.Driver field ("postgres" or "sqlite")
- main.go: SQLite connection with WAL mode, single writer
- server/setup: quest check + preset selection steps
- server/api: /dashboard with live stats
- .github/workflows: Docker in release, deduplicate docker.yml

server/api/api_server.go

@@ -9,6 +9,8 @@ import (
 	"sync"
 	"time"
 
+	dbutil "erupe-ce/common/db"
+
 	"github.com/gorilla/handlers"
 	"github.com/gorilla/mux"
 	"github.com/jmoiron/sqlx"
@@ -33,6 +35,7 @@ type APIServer struct {
 	sessionRepo    APISessionRepo
 	eventRepo      APIEventRepo
 	httpServer     *http.Server
+	startTime      time.Time
 	isShuttingDown bool
 }
 
@@ -45,19 +48,26 @@ func NewAPIServer(config *Config) *APIServer {
 		httpServer:  &http.Server{},
 	}
 	if config.DB != nil {
-		s.userRepo = NewAPIUserRepository(config.DB)
-		s.charRepo = NewAPICharacterRepository(config.DB)
-		s.sessionRepo = NewAPISessionRepository(config.DB)
-		s.eventRepo = NewAPIEventRepository(config.DB)
+		wdb := dbutil.Wrap(config.DB)
+		s.userRepo = NewAPIUserRepository(wdb)
+		s.charRepo = NewAPICharacterRepository(wdb)
+		s.sessionRepo = NewAPISessionRepository(wdb)
+		s.eventRepo = NewAPIEventRepository(wdb)
 	}
 	return s
 }
 
 // Start starts the server in a new goroutine.
 func (s *APIServer) Start() error {
+	s.startTime = time.Now()
+
 	// Set up the routes responsible for serving the launcher HTML, serverlist, unique name check, and JP auth.
 	r := mux.NewRouter()
 
+	// Dashboard routes (before catch-all)
+	r.HandleFunc("/dashboard", s.Dashboard)
+	r.HandleFunc("/api/dashboard/stats", s.DashboardStatsJSON).Methods("GET")
+
 	// Legacy routes (unchanged, no method enforcement)
 	r.HandleFunc("/launcher", s.Launcher)
 	r.HandleFunc("/login", s.Login)