feat: agent keeps SSH file sessions and runs file operations on the host by commands

internal/proto/proto.go

@@ -167,6 +167,11 @@ const (
 	TaskDBAdd      = "db.add"      // add a row
 	TaskDBDel      = "db.del"      // delete rows by their keys
 	TaskDBSQL      = "db.sql"      // run a statement typed in the panel
+	TaskSSHFSOpen  = "sshfs.open"  // connect to an SSH host for a file pane; result {id, home}
+	TaskSSHFSClose = "sshfs.close" // drop that connection
+	TaskSSHFSOp    = "sshfs.op"    // a file operation on the host: list, read, write, mkdir, delete, deltree, move, copy, stat, chmod
+	TaskSSHFSSend  = "sshfs.send"  // a file of the host to the browser in pieces (FSXferArgs with Conn)
+	TaskSSHFSPut   = "sshfs.put"   // a file from the browser to the host in pieces
 	TaskFSShipOut  = "fs.ship.out" // pack a file or folder and send it to another machine
 	TaskFSShipIn   = "fs.ship.in"  // unpack what another machine sends
 )
@@ -186,6 +191,18 @@ type FSXferArgs struct {
 	Xfer  string `json:"xfer"`
 	Size  int64  `json:"size"`
 	Chunk int    `json:"chunk"`
+	// Conn is the SSH file connection the file is on (sshfs.send, sshfs.put).
+	Conn string `json:"conn,omitempty"`
+}
+
+// SSHFSArgs are the arguments of the sshfs.* tasks: the connection (Conn), or
+// where to connect (SSH, for open); for an operation its name (Op) and its
+// arguments (Args) in the shapes of the fs.* tasks.
+type SSHFSArgs struct {
+	Conn string          `json:"conn,omitempty"`
+	SSH  *SSHTarget      `json:"ssh,omitempty"`
+	Op   string          `json:"op,omitempty"`
+	Args json.RawMessage `json:"args,omitempty"`
 }
 
 // TaskEnvelope is what the agent fetches for a task id.