refactor: adopt portigo infrastructure patterns

Add config package with build-tag-switched dev/prod environments,
structured logging via zerolog, Taskfile for dev workflow, golangci-lint
config, testutil package, and improved DB setup with proper SQLite
pragmas and cleanup. Rename sqlc output package from gen to repository.

Switch to allowlist .gitignore, Alpine+UPX+scratch Dockerfile, and
CI pipeline with test/lint gates before deploy.

ui/status.go

@@ -1,8 +1,7 @@
 package ui
 
 import (
-	"os"
-
+	"github.com/ryanhamamura/c4/config"
 	"github.com/ryanhamamura/c4/game"
 	"github.com/ryanhamamura/via/h"
 )
@@ -118,10 +117,7 @@ func PlayerInfo(g *game.Game, myColor int) h.H {
 }
 
 func getBaseURL() string {
-	if url := os.Getenv("APP_URL"); url != "" {
-		return url
-	}
-	return "https://games.adriatica.io"
+	return config.Global.AppURL
 }
 
 func InviteLink(gameID string) h.H {