fix: correct DockerfileUbuntu package list, add rustup install, and fix terminal init sequence

- Fix typo in DockerfileDrive COPY command (COpy -> COPY)
- Add xterm, valgrind, ack, irssi, lynx packages to DockerfileUbuntu
- Add rustup installation with nightly toolchain in DockerfileUbuntu
- Fix r binary move path in DockerfileUbuntu (add trailing /r)
- Remove CMD ["r"] from DockerfileUbuntu
- Replace terminal.html onopen handler: call fitAddon.fit() and send form feed instead of hardcoded green text
- Add $HOME/bin to PATH in .bashrc
- Add resize command to .bashrc for terminal geometry sync
- Delete terminal/.rcontext.txt file entirely

terminal/.bashrc

@@ -100,12 +100,15 @@ fi
 #if [ -f /etc/bash_completion ] && ! shopt -oq posix; then
 #    . /etc/bash_completion
 #fi
+
 export PS1="root@snek: "
 
 if [ -d "$HOME/.local/bin" ] ; then
     PATH="$HOME/.local/bin:$PATH"
 fi
-
+if [ -d "$HOME/bin" ] ; then
+    PATH="$HOME/bin:$PATH"
+fi
 
 function r_update(){
     if [ -f "r" ]; then
@@ -116,6 +119,9 @@ function r_update(){
     mv r /usr/local/bin/r
 }
 
+
+resize > /dev/null 
+
 r_update 
 
 r