feat(web): add dockerized web UI with comic library browser

Adds a `yoink serve` command that starts an HTTP server with a
Sonarr/MeTube-inspired dark UI. Features a URL input bar for
triggering downloads, a 150x300 cover grid with filter and sort
controls, a live download queue strip, and toast notifications.

Includes Dockerfile (multi-stage, distroless runtime) and
docker-compose.yml for easy deployment.

.gitignore

@@ -19,4 +19,15 @@ go.work
 go.work.sum
 
 # env file
-.env
+.env
+
+# Built binary
+yoink
+yoink.exe
+
+# Comic library (downloaded content)
+library/
+
+# IDE
+.vscode/
+.idea/