feat: initial Minipaste

- MinIO-backed paste storage with 8-char base62 IDs
- Paste expiry (1m, 1h, 1d, 1w, never) stored in object metadata
- Raw plain-text endpoint at /raw/:id
- Syntax highlighting in editor and paste view via highlight.js
- In-editor highlight overlay with live language switching
- Download button with correct file extension per language
- Auto-redirect to paste after creation

.devcontainer/devcontainer.json

@@ -0,0 +1,12 @@
+{
+	"name": "Minipaste Dev Container",
+	"image": "mcr.microsoft.com/devcontainers/javascript-node:24-bookworm",
+	"forwardPorts": [3000],
+	"portsAttributes": {
+		"3000": {
+			"label": "App",
+			"onAutoForward": "notify"
+		}
+	},
+	"postCreateCommand": "npm install"
+}