refactor(shell): extract _fish_mkdir_p utility; improve poke output

- Add _fish_mkdir_p: reusable mkdir -p with three output modes:
  --path (default): "Created: ~/full/path/" on one line
  --tree: dimmed existing anchor + cyan tree of newly-created dirs
  --silent: no output
  HOME is substituted with ~ in all output paths
- Refactor poke to delegate to _fish_mkdir_p --tree; removes inline
  mkdir/echo logic and gains ~ substitution and per-dir tree output

functions/_fish_mkdir_p.fish

@@ -0,0 +1,62 @@
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+# mkdir -p with configurable output.
+#
+# Flags:
+#   --path / -p   (default) Print "Created: ~/full/path/" on one line
+#   --tree / -t             Tree view: dimmed existing anchor + cyan new dirs
+#   --silent / -s           No output
+#
+# Usage: _fish_mkdir_p [--path|--tree|--silent] <dir>
+function _fish_mkdir_p --description 'mkdir -p with configurable verbose output'
+    set -l mode path
+    set -l target
+
+    for _arg in $argv
+        switch $_arg
+            case -s --silent
+                set mode silent
+            case -t --tree
+                set mode tree
+            case -p --path
+                set mode path
+            case '*'
+                set target $_arg
+        end
+    end
+
+    test -n "$target"; or return 1
+    test -d "$target"; and return 0
+
+    # Walk up to find deepest existing ancestor; collect dirs to create (shallowest first).
+    set -l to_create
+    set -l cursor $target
+    while not test -d $cursor
+        set -p to_create $cursor
+        set -l up (dirname $cursor)
+        test "$up" = "$cursor"; and break  # filesystem root guard
+        set cursor $up
+    end
+
+    mkdir -p $target; or return $status
+    test $mode = silent; and return 0
+
+    if test $mode = path
+        set -l display (string replace -- "$HOME" "~" $target)"/"
+        echo (set_color --bold cyan)"Created: "(set_color cyan)"$display"(set_color normal)
+        return 0
+    end
+
+    # Tree mode: dimmed existing anchor, then cyan new dirs.
+    echo (set_color --bold cyan)"Created:"(set_color normal)
+    set -l anchor (string replace -- "$HOME" "~" $cursor)"/"
+    echo (set_color brblack)" $anchor"(set_color normal)
+    set -l i 1
+    while test $i -le (count $to_create)
+        set -l spaces (string repeat -n (math "($i - 1) * 4") " ")
+        set -l name (basename $to_create[$i])"/"
+        echo (set_color cyan)" $spaces└── $name"(set_color normal)
+        set i (math $i + 1)
+    end
+end

functions/poke.fish

@@ -8,10 +8,7 @@ function poke --description 'touch with automatic parent directory creation'
     end
     for _path in $argv
         set -l _dir (dirname $_path)
-        if not test -d $_dir
-            mkdir -p $_dir
-            and echo (set_color --bold cyan)"Created: "(set_color cyan)"$_dir"(set_color normal)
-        end
+        _fish_mkdir_p --tree $_dir
         touch $_path
     end
 end