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/default.nix

@@ -2,9 +2,15 @@
   imports = [
     # General Configuration
     ./autocmds.nix
-    ./keymaps.nix
     ./options.nix
 
+    # Keymaps
+    ./keymaps/general.nix
+    ./keymaps/buffers.nix
+    ./keymaps/windows.nix
+    ./keymaps/find.nix
+    ./keymaps/git.nix
+
     # Themes & Appearance
     ./plugins/themes/default.nix
 
@@ -22,8 +28,8 @@
     # Editor Enhancements
     ./plugins/editor/commentary.nix
     ./plugins/editor/harpoon.nix
+    ./plugins/editor/maximize.nix
     ./plugins/editor/sessions.nix
-    ./plugins/editor/smart-splits.nix
     ./plugins/editor/surround.nix
     ./plugins/editor/treesitter.nix