docs(functions): add man-page headers to branch, fc, gitup, sudo-toggle

These four were the only documented functions with no comment header,
carrying just a one-line description. Content is merged from their manual
entries plus what the implementations actually do (fc's vi fallback and
empty-buffer abort, sudo-toggle's credential-cache clear), so the headers
are a superset of Section 5 rather than a copy of it.

functions/branch.fish

@@ -1,4 +1,25 @@
-# Switch to or create a git branch
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+# CATEGORY
+#   04-git-and-version-control
+#
+# SYNOPSIS
+#   branch <branch_name>
+#
+# DESCRIPTION
+#   Switches to a local git branch, creating it if it does not already
+#   exist. Extra arguments are forwarded to git checkout.
+#
+# ARGUMENTS
+#   branch_name   Branch to switch to or create
+#
+# RETURNS
+#   0  Branch checked out or created
+#   1  Not inside a git work tree
+#
+# EXAMPLE
+#   branch feature/new-ui
 function branch --description 'Switch to or create a git branch'
     if not git rev-parse --is-inside-work-tree >/dev/null 2>&1
         echo "Not a git repo."

functions/fc.fish

@@ -1,4 +1,28 @@
-# Edit and execute the last command (Bash-style fc)
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+# CATEGORY
+#   03-editors-and-viewers
+#
+# SYNOPSIS
+#   fc [command_prefix]
+#
+# DESCRIPTION
+#   Edits the last shell command -- or the most recent one matching a
+#   prefix -- in $EDITOR, then executes the result. Bash-style fc
+#   behaviour. Falls back to vi when $EDITOR is unset, and aborts without
+#   executing if the buffer is left empty.
+#
+# ARGUMENTS
+#   command_prefix   Search history for the newest command matching this
+#
+# RETURNS
+#   The edited command's exit status, or a message when history lookup
+#   found nothing.
+#
+# EXAMPLE
+#   fc
+#   fc git
 function fc --description 'Edit and execute the last command (Bash-style fc)'
     set -l tmpfile (mktemp /tmp/fish_fc.XXXXXX).fish
 

functions/gitup.fish

@@ -1,4 +1,26 @@
-# Fetch updates and show git status
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+# CATEGORY
+#   04-git-and-version-control
+#
+# SYNOPSIS
+#   gitup [args...]
+#
+# DESCRIPTION
+#   Fetches updates from the remote and shows git status. Extra arguments
+#   are forwarded to git fetch.
+#
+# ARGUMENTS
+#   args...   Forwarded verbatim to git fetch
+#
+# RETURNS
+#   0  Fetch and status succeeded
+#   1  Not inside a git work tree
+#
+# EXAMPLE
+#   gitup
+#   gitup --all
 function gitup --description 'Fetch updates and show git status'
     # Check if we are even in a git repository
     if not git rev-parse --is-inside-work-tree >/dev/null 2>&1

functions/sudo-toggle.fish

@@ -1,3 +1,23 @@
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+# CATEGORY
+#   07-system-and-monitoring
+#
+# SYNOPSIS
+#   sudo-toggle
+#
+# DESCRIPTION
+#   Toggles the sudo NOPASSWD rule on and off via
+#   /etc/sudoers.d/nofail-toggle. Useful for automated tasks that would
+#   otherwise require a password entry. Clears the sudo credential cache
+#   when re-enabling, so the lockdown takes effect immediately.
+#
+# RETURNS
+#   0  Rule toggled
+#
+# EXAMPLE
+#   sudo-toggle
 function sudo-toggle --description 'Toggle sudo password requirement on/off'
     # Check the file size using sudo stat to see if our bypass rule is active
     set -l file_size (sudo stat -c %s /etc/sudoers.d/nofail-toggle 2>/dev/null)