nvim,tmux: move split nav to Alt+hjkl, add tab cycling, set DIFFPROG

- smart-splits: C-hjkl → A-hjkl for split/pane navigation
- tmux: C-hjkl → M-hjkl to keep seamless smart-splits integration
- keymaps: add A-Tab / A-S-Tab for vim tab cycling
- profile: set DIFFPROG="nvim -d" for pacdiff

dot_config/nvim/lua/keymaps.lua

@@ -41,3 +41,7 @@ map({ "n", "i" }, "<C-s>", "<cmd>w<cr>", { desc = "Save" })
 -- Quit
 map("n", "<leader>q", "<cmd>q<cr>", { desc = "Quit" })
 map("n", "<leader>Q", "<cmd>qa<cr>", { desc = "Quit all" })
+
+-- Tab navigation
+map("n", "<A-Tab>",   "<cmd>tabnext<cr>",     { desc = "Next tab" })
+map("n", "<A-S-Tab>", "<cmd>tabprevious<cr>", { desc = "Prev tab" })

dot_config/nvim/lua/plugins/ui.lua

@@ -9,10 +9,10 @@ return {
     },
     keys = {
       -- Navigate
-      { "<C-h>", function() require("smart-splits").move_cursor_left()  end, mode = { "n", "t" }, desc = "Move to left split/pane"  },
-      { "<C-j>", function() require("smart-splits").move_cursor_down()  end, mode = { "n", "t" }, desc = "Move to lower split/pane" },
-      { "<C-k>", function() require("smart-splits").move_cursor_up()    end, mode = { "n", "t" }, desc = "Move to upper split/pane" },
-      { "<C-l>", function() require("smart-splits").move_cursor_right() end, mode = { "n", "t" }, desc = "Move to right split/pane" },
+      { "<A-h>", function() require("smart-splits").move_cursor_left()  end, mode = { "n", "t" }, desc = "Move to left split/pane"  },
+      { "<A-j>", function() require("smart-splits").move_cursor_down()  end, mode = { "n", "t" }, desc = "Move to lower split/pane" },
+      { "<A-k>", function() require("smart-splits").move_cursor_up()    end, mode = { "n", "t" }, desc = "Move to upper split/pane" },
+      { "<A-l>", function() require("smart-splits").move_cursor_right() end, mode = { "n", "t" }, desc = "Move to right split/pane" },
       -- Resize
       { "<C-A-h>", function() require("smart-splits").resize_left()  end, desc = "Resize left"  },
       { "<C-A-j>", function() require("smart-splits").resize_down()  end, desc = "Resize down"  },

dot_config/tmux/tmux.conf

@@ -24,10 +24,10 @@ set -g allow-rename off
 setw -g pane-border-status top
 
 #### PANE NAVIGATION (no prefix — smart-splits passthrough) ####
-bind -n C-h select-pane -L
-bind -n C-j select-pane -D
-bind -n C-k select-pane -U
-bind -n C-l select-pane -R
+bind -n M-h select-pane -L
+bind -n M-j select-pane -D
+bind -n M-k select-pane -U
+bind -n M-l select-pane -R
 
 #### PANE NAVIGATION (with prefix) ####
 bind h select-pane -L

dot_profile.tmpl

@@ -11,6 +11,7 @@ export PATH="${PATH}:{{ .chezmoi.homeDir }}/.cargo/bin"
 export ZDOTDIR="{{ .chezmoi.homeDir }}/.config/zsh"
 
 export EDITOR="nvim"
+export DIFFPROG="nvim -d"
 
 export FZF_DEFAULT_OPTS="$FZF_DEFAULT_OPTS \
   --highlight-line \