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/detach.fish

@@ -0,0 +1,45 @@
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+function detach
+    set -l show_help 0
+    set -l args
+
+    for arg in $argv
+        switch $arg
+            case -h --help
+                set show_help 1
+            case --version
+                echo "detach 1.0.0"
+                return
+            case '-*' '--*'
+                echo "❌ Unknown option: $arg"
+                echo "Run 'detach --help' for usage."
+                return 1
+            case '*'
+                set args $args $arg
+        end
+    end
+
+    if test $show_help -eq 1
+        echo "Usage: detach [command...]"
+        echo "Runs a command in the background, fully detached from the terminal."
+        echo
+        echo "Options:"
+        echo "  -h, --help        Show this help message"
+        echo "  --version         Show version information"
+        echo
+        echo "Example:"
+        echo "  detach firefox"
+        echo "  detach rsync -a ./data remote:/backup/"
+        return
+    end
+
+    if test (count $args) -eq 0
+        echo "❌ No command provided."
+        echo "Run 'detach --help' for usage."
+        return 1
+    end
+
+    nohup $args >/dev/null 2>&1 &
+end