Fix real hardware/busybox breakage: dead compgen dependency, unreliable sourced-path detection, and fork-heavy pipelines in fx sources; verified against busybox ash+awk directly

contrib/fx/sources.d/40-pathfuzzy.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 # PATH-fuzzy source: if the first word isn't a known command, alias, or
 # function, offer a function wrapping the closest-spelled real command
 # as a candidate -- as a fix you approve through the normal f() flow,
@@ -7,6 +7,12 @@
 # otherwise), so an alias-based fix silently does nothing when f/fx run
 # inside a script.
 #
+# Pure POSIX: walks $PATH directly instead of `compgen -c`, which is a
+# bash-only builtin and does not exist under busybox ash -- this source
+# used to be dead weight on exactly the minimal/embedded shells this
+# project targets. Tested against busybox ash + busybox awk directly,
+# not just bash + gawk.
+#
 # Uses Damerau-Levenshtein-lite (edit distance + adjacent transposition)
 # so the canonical "gti" -> "git" typo scores 1, not 2 -- plain Hamming
 # or substitution-only distance ties it with unrelated 3-letter commands
@@ -15,9 +21,11 @@ cmd="$1"
 first_word=$(printf '%s' "$cmd" | awk '{print $1}')
 [ -n "$first_word" ] || exit 0
 command -v "$first_word" >/dev/null 2>&1 && exit 0
-type "$first_word" >/dev/null 2>&1 && exit 0
 
-compgen -c 2>/dev/null | sort -u | awk -v target="$first_word" '
+IFS=:
+for d in $PATH; do
+    ls "$d" 2>/dev/null
+done | sort -u | awk -v target="$first_word" '
 function min3(a, b, c) { return (a < b ? (a < c ? a : c) : (b < c ? b : c)) }
 function distance(a, b,    n, m, i, j, ca, cb, cost, tmp) {
     n = length(a); m = length(b)