Scaffold the dsh-slopo bundle and port slopo's three agent skills

The three SKILL.md files are ports of the configs slopo 0.8.0 ships for
Claude Code, not new prose. What changed is the mechanics:

  * name + description frontmatter, both required by dsh
  * disable-model-invocation: true kept verbatim -- dsh has the same key,
    and slopo makes that choice for a reason (every one of these commands
    can spend minutes embedding)
  * allowed-tools / argument-hint / arguments dropped, not dsh keys
  * the !`slopo ...` shell-injection directive replaced with an
    instruction to call the slopo tool plus an explicit failure check,
    because dsh skill bodies do not execute commands

The guidance prose is quoted from slopo; NOTICE.md records the mapping and
the licence obligation that follows from it (AGPL-3.0-or-later, matching
upstream and the LICENSE file fetched from it).

.gitignore

@@ -0,0 +1,2 @@
+node_modules/
+*.log