refactor(bin): cut per-invocation load and repair broken skill references

diagnose read its feedback-loops reference unconditionally, so every
invocation paid for guidance most runs never used; the read is conditional
again and the per-invocation cost drops from 1,278 to 831 words. Its HITL
template moves to assets/ because it is copied out, not read as reference.
prototype's two branch flows move into references/ for the same reason —
only one branch is ever taken.

research could not search the codebase it was asked to research without Grep
and Glob. caveman's description had grown into a paragraph where one sentence
carries the trigger. Four references pointed at things that do not exist: a
to-prd skill, a /setup-matt-pocock-skills command, two cross-skill ../ links
that only resolve in the source tree, and two places calling this project's
Gitea host GitHub.

Addresses #114.

plugins/bin/skills/diagnose/references/feedback-loops.md

@@ -13,7 +13,7 @@ A feedback loop is a fast, deterministic, agent-runnable pass/fail signal for th
 7. **Property / fuzz loop.** If the bug is "sometimes wrong output", run 1000 random inputs and look for the failure mode.
 8. **Bisection harness.** If the bug appeared between two known states (commit, dataset, version), automate "boot at state X, check, repeat" so you can `git bisect run` it.
 9. **Differential loop.** Run the same input through old-version vs new-version (or two configs) and diff outputs.
-10. **HITL bash script.** Last resort. If a human must click, drive _them_ with `scripts/hitl-loop.template.sh` so the loop is still structured. Captured output feeds back to you.
+10. **HITL bash script.** Last resort. If a human must click, drive _them_ with `assets/hitl-loop.template.sh` so the loop is still structured. Captured output feeds back to you.
 
 ## Iterate on the loop itself