Self-healing autopoietic shell: f(), tests, docs, interactive demo, fx fix-source layer

src/f.sh

@@ -0,0 +1,31 @@
+#!/bin/sh
+# Self-healing shell loop: run a command, and on failure ask for a fix,
+# persist it keyed by the exact command line, then retry. On future
+# calls with the same command, the learned fix is applied proactively
+# before the command itself runs.
+#
+# State lives in ./p as "command=fix" lines, one per learned command.
+# Copy p to another machine to transfer everything this shell has learned.
+#
+# Usage:
+#   . f.sh
+#   f some-command-that-might-fail --with args
+
+f() {
+    FIX=""
+    if [ -f p ]; then
+        while IFS= read -r line; do
+            case "$line" in
+                "$*="*) FIX="${line#"$*="}" ;;
+            esac
+        done < p
+    fi
+
+    until { eval "$FIX" 2>/dev/null; "$@"; }; do
+        printf '\n[LEARN] "%s" failed. Enter a fix (blank to give up): ' "$*" >&2
+        read -r n
+        [ -n "$n" ] || return 1
+        echo "$*=$n" >> p
+        FIX="$n"
+    done
+}