Add development-scripts agent skill

Ports generic-scripts-module-v1 into a routed skill: module anatomy, shared
loggers/base modules, Taskfile integration, workflows, and pattern decisions.

Fixes a latent defect in the loggers example that silenced all logging in the
module scaffold: loggers/lib/--index-api.sh now sources --env-vars-reader.sh,
and the reader preserves already-exported values so caller overrides still win.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

assets/loggers/lib/--index-api.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+# -------------------------------------------------------------------------------------
+# IBM Confidential
+# 6949-70F, 6949-80D
+# © Copyright IBM Corp. 2018, 2024
+# US Government Users Restricted Rights - Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp.
+# -------------------------------------------------------------------------------------
+
+#
+#       --> logger level flags and padding strings must exist before any logger
+#           function runs; the reader preserves already-exported values, so this
+#           is safe to source repeatedly and from any dependent module
+#
+. ./.scripts/loggers/lib/--env-vars-reader.sh
+
+. ./.scripts/loggers/lib/-enable-trailing-new-line.sh
+
+. ./.scripts/loggers/lib/-info.sh
+. ./.scripts/loggers/lib/-trace.sh
+. ./.scripts/loggers/lib/-debug.sh
+. ./.scripts/loggers/lib/-error.sh
+. ./.scripts/loggers/lib/-warn.sh
+
+. ./.scripts/loggers/lib/-empty-line.sh
+. ./.scripts/loggers/lib/-waiting-dot.sh