chore(restructure): reorganize project layout

- Reorganize internal packages and overall project structure
- Update imports and wiring to match the new layout
- Separate HTTP parsing and streaming from the server package
- Separate middleware from the server package
- Separate session registry from the session package
- Move HTTP, HTTPS, and TCP servers to the transport package
- Session package no longer starts the TCP server directly
- Server package no longer starts HTTP/HTTPS servers on initialization
- Forwarder no longer handles accepting TCP requests
- Move session details to the types package
- HTTP/HTTPS initialization is now the responsibility of main

types/types.go

@@ -1,5 +1,7 @@
 package types
 
+import "time"
+
 type Status int
 
 const (
@@ -27,6 +29,14 @@ type SessionKey struct {
 	Type TunnelType
 }
 
+type Detail struct {
+	ForwardingType string    `json:"forwarding_type,omitempty"`
+	Slug           string    `json:"slug,omitempty"`
+	UserID         string    `json:"user_id,omitempty"`
+	Active         bool      `json:"active,omitempty"`
+	StartedAt      time.Time `json:"started_at,omitempty"`
+}
+
 var BadGatewayResponse = []byte("HTTP/1.1 502 Bad Gateway\r\n" +
 	"Content-Length: 11\r\n" +
 	"Content-Type: text/plain\r\n\r\n" +