feat(clipboard): add win32yank fallback for WSL2

y, p, paste, and hist now try win32yank.exe after wl-copy/wl-paste
and xclip, so clipboard access works under WSL2 once win32yank is
installed and reachable through WSL interop. Updates the OS
compatibility docs accordingly.

functions/hist.fish

@@ -12,7 +12,8 @@
 #
 # DESCRIPTION
 #   Searches fish history interactively using fzf, inserts the selected command
-#   into the command line, and copies it to the clipboard via wl-copy.
+#   into the command line, and copies it to the clipboard via wl-copy (falls
+#   back to win32yank on WSL2).
 #
 # EXIT STATUS
 #   0  Command selected and inserted, or fzf was cancelled
@@ -36,7 +37,11 @@ function hist --description 'Search fish history and put it in the prompt'
         # Strip the timestamp for the final output
         set -l command (echo $selected | string replace -r '^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2} ' '')
 
-        echo $command | wl-copy 2>/dev/null
+        if type -q wl-copy
+            echo $command | wl-copy 2>/dev/null
+        else if type -q win32yank.exe
+            echo $command | win32yank.exe -i --crlf 2>/dev/null
+        end
         commandline -r $command
     end
 end

functions/p.fish

@@ -8,8 +8,8 @@
 #   p [args...]
 #
 # DESCRIPTION
-#   Outputs clipboard contents to stdout. Uses wl-paste on Wayland,
-#   falls back to xclip on X11. Supports -h/--help for usage info.
+#   Outputs clipboard contents to stdout. Uses wl-paste on Wayland, xclip on
+#   X11, or win32yank on WSL2. Supports -h/--help for usage info.
 #
 # ARGUMENTS
 #   -h, --help  Show usage help
@@ -47,8 +47,10 @@ function p --description 'Put from clipboard'
         set paste_cmd wl-paste
     else if type -q xclip
         set paste_cmd xclip -selection clipboard -o
+    else if type -q win32yank.exe
+        set paste_cmd win32yank.exe -o --lf
     else
-        echo "Error: No clipboard provider (wl-paste or xclip) found." >&2
+        echo "Error: No clipboard provider (wl-paste, xclip, or win32yank) found." >&2
         return 1
     end
 

functions/paste.fish

@@ -8,8 +8,8 @@
 #   paste [args...]
 #
 # DESCRIPTION
-#   Outputs clipboard contents to stdout. Uses wl-paste on Wayland,
-#   falls back to xclip on X11.
+#   Outputs clipboard contents to stdout. Uses wl-paste on Wayland, xclip on
+#   X11, or win32yank on WSL2.
 #
 # ARGUMENTS
 #   args...  Arguments forwarded to the clipboard tool
@@ -28,8 +28,10 @@ function paste --description 'Paste from clipboard'
         wl-paste $argv
     else if type -q xclip
         xclip -selection clipboard -o $argv
+    else if type -q win32yank.exe
+        win32yank.exe -o --lf $argv
     else
-        echo "Error: Neither wl-paste nor xclip found." >&2
+        echo "Error: No clipboard provider (wl-paste, xclip, or win32yank) found." >&2
         return 1
     end
 end

functions/y.fish

@@ -8,8 +8,8 @@
 #   y [text...]
 #
 # DESCRIPTION
-#   Copies text to the system clipboard using wl-copy (Wayland) or xclip (X11).
-#   Reads from stdin when no arguments are given.
+#   Copies text to the system clipboard using wl-copy (Wayland), xclip (X11),
+#   or win32yank (WSL2). Reads from stdin when no arguments are given.
 #
 # ARGUMENTS
 #   text  Text to copy; reads from stdin if omitted
@@ -42,8 +42,10 @@ function y --description 'Yank to clipboard'
         set copy_cmd wl-copy
     else if type -q xclip
         set copy_cmd xclip -selection clipboard
+    else if type -q win32yank.exe
+        set copy_cmd win32yank.exe -i --crlf
     else
-        echo "Error: No clipboard provider (wl-copy or xclip) found." >&2
+        echo "Error: No clipboard provider (wl-copy, xclip, or win32yank) found." >&2
         return 1
     end