refactor: reorganize keymaps into semantic namespaces

Restructure keybindings for improved discoverability and consistency
with WezTerm/XMonad configurations. Separate keymaps from plugin
configurations following single responsibility principle.

Changes:
- Create keymaps/ directory with semantic grouping:
  - general.nix: leader setup, page navigation
  - buffers.nix: buffer operations (bq, bQ, bl)
  - windows.nix: window operations (ws, wv, wq, wQ, wm)
  - find.nix: telescope find operations (ff, fg, fh, fc)
  - git.nix: unified git operations from gitsigns/fugitive/telescope

- Adopt consistent q/Q pattern across containers:
  - bq/bQ for buffer quit (current/all others)
  - wq/wQ for window quit (current/all others)
  - Mirrors WezTerm's LEADER+p q / LEADER+t q pattern

- Extract keymaps from plugin files:
  - telescope.nix: config only, keymaps moved to find.nix
  - fugitive.nix: config only, keymaps moved to git.nix
  - gitsigns.nix: config only, keymaps moved to git.nix
  - snacks.nix: config only, keymaps moved to buffers.nix
  - maximize.nix: config only, keymap moved to windows.nix

- Remove smart-splits.nix (functionality replaced by native window ops)

- Maintain navigation on dedicated modifiers (Ctrl+arrows/PageUp/PageDown)
  for consistency with WezTerm (ALT) and XMonad (Super)

config/plugins/collections/snacks.nix

@@ -1,4 +1,4 @@
-{...}:{
+{...}: {
   plugins.snacks = {
     enable = true;
 
@@ -12,30 +12,4 @@
       };
     };
   };
-
-  keymaps = [
-    {
-      mode = ["n"];
-      key = "<leader>q";
-      action = {
-        __raw = "function() require('snacks').bufdelete() end"; 
-      };
-      options = {
-        desc = "Close current buffer";
-        silent = true;
-      };
-    }
-    
-    {
-      mode = ["n"];
-      key = "<leader>Q";
-      action = {
-        __raw = "function() require('snacks').bufdelete.other() end";
-      };
-      options = {
-        desc = "Close other buffers";
-        silent = true;
-      };
-    }
-  ];
 }