chore(zsh): removed oh-my-zsh and made the config cleaner

.config/zsh/main.zsh

@@ -1,25 +1,22 @@
 
-HISTSIZE=10000000
-SAVEHIST=10000000
+HISTSIZE=100000000
+SAVEHIST=100000000
 setopt BANG_HIST                 # Treat the '!' character specially during expansion.
 setopt EXTENDED_HISTORY          # Write the history file in the ":start:elapsed;command" format.
 setopt INC_APPEND_HISTORY        # Write to the history file immediately, not when the shell exits.
 setopt SHARE_HISTORY             # Share history between all sessions.
-setopt HIST_EXPIRE_DUPS_FIRST    # Expire duplicate entries first when trimming history.
-setopt HIST_IGNORE_DUPS          # Don't record an entry that was just recorded again.
 setopt HIST_FIND_NO_DUPS         # Do not display a line previously found.
 setopt HIST_IGNORE_SPACE         # Don't record an entry starting with a space.
 setopt HIST_REDUCE_BLANKS        # Remove superfluous blanks before recording entry.
+setopt HIST_SAVE_NO_DUPS
 setopt HIST_VERIFY
 
 export EDITOR=nvim
+export VISUAL=nvim
 export READER=mupdf
 
 enable-fzf-tab
 
-# opam configuration
-source $HOME/.opam/opam-init/init.zsh > /dev/null 2>&1 || true
-
 eval "$(direnv hook zsh)"
 if [[ $(uname) == "Darwin" ]]; then
     eval "$(/opt/homebrew/bin/brew shellenv)"