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

functions/bkg.fish

@@ -0,0 +1,26 @@
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+# Function to run a command in the background, detached from the terminal.
+# This prevents the command from being terminated when the terminal is closed.
+# All output (stdout and stderr) is discarded.
+#
+# Usage:
+#   bkg <command> [arguments...]
+#
+# Example:
+#   bkg firefox
+#   bkg code .
+#
+function bkg
+    # Check if a command was provided as an argument.
+    if test -z "$argv[1]"
+        echo "Usage: bkg <command> [arguments...]"
+        return 1
+    end
+
+    # Run the command using nohup to make it immune to hangups (like closing the terminal).
+    # Redirect both stdout and stderr to /dev/null to discard all output.
+    # The final ampersand (&) sends the entire process to the background.
+    nohup $argv &>/dev/null &
+end