--- "mattpocock-skills": patch --- Stop skills from trying to reach user-invoked skills through the Skill tool: fix cross-skill references that violated the "no other skill can call it" invariant in `.agents/invocation.md`, in `to-spec`, `wayfinder`, `to-tickets`, `triage`, `code-review`, and `diagnosing-bugs`. - `to-spec`, `wayfinder`, `to-tickets`, `triage`, and `code-review` each carried a precondition ("...run `/setup-matt-pocock-skills` if not") that PR #878 rewrote into a literal `Call the Skill tool with "setup-matt-pocock-skills"` instruction. `setup-matt-pocock-skills` is user-invoked, so none of these skills (user-invoked or model-invoked) can call it. Reworded all five as instructions for the agent to tell the human to run it instead. - `diagnosing-bugs`'s Phase 6 post-mortem hand off to `improve-codebase-architecture` (also user-invoked) the same way, from an autonomous, often-unattended bug-fixing flow with no human in the loop to catch the failed call. Removed the hand-off outright rather than softening it, since it rarely fired in practice. Phase 6 is now "Cleanup" only; the mechanical checklist is untouched. - Added a carve-out paragraph to `.agents/invocation.md`'s "Dependencies between them" section: the `Call the Skill tool with "name"` convention only applies when the named skill is model-invoked. This is the section PR #878 introduced without reconciling it against the user-invoked/model-invoked invariant stated eight lines above it; the gap is most of why this bug reached six call sites instead of one. Fixes #453.