feat: initial fish shell configuration

- Core config layered on CachyOS base with Catppuccin Mocha theming
- Fisher plugins: fzf.fish, catppuccin, autopair, replay, puffer-fish, magic-enter, spark
- Smart CLI wrappers with fallbacks (bat, lsd, btop, dust, prettyping)
- Custom functions: git, docker, network, kitty, AI session management
- Extensive abbreviation system for keyboard-driven workflows
- Secrets/local sourcing pattern for private and machine-specific config
- README with full documentation and personalization guide
- AGPLv3+ license with copyright headers on all source files

fish_plugins

@@ -0,0 +1,8 @@
+catppuccin/fish
+patrickf1/fzf.fish
+jorgebucaran/fisher
+jorgebucaran/autopair.fish
+jorgebucaran/replay.fish
+nickeb96/puffer-fish
+mattmc3/magic-enter.fish
+jorgebucaran/spark.fish