feat(grill-family): adapt grilling/grill-me/grill-with-docs from mattpocock @84fdeffd (MIT)

Convergent phase of the brainstorm flow: user says «хватит, к промоушену» →
grill session (design tree, rounds, frontier, numbered Q's with recommended
answers) → decision record. Adaptations to our conventions:
- grill-with-docs writes .wiki/concepts/<topic>-decision.md (project-discipline
  Rule 1) or appends to .brainstorm/ running record in the workshop zone
- grilling sub-agent line made cross-agent honest (look up facts directly
  when no subagent spawning)
- disable-model-invocation: true on both user wrappers
Provenance pinned to real commit 84fdeffd (not TBD). README table updated.
lint: 0/0; ~/.claude/skills now 41.

README.md

@@ -113,6 +113,7 @@ an explicit `adapted-from` marker in its frontmatter.
 |---|---|
 | `caveman`, `caveman-commit`, `caveman-compress`, `caveman-help`, `caveman-review` | `adapted-from: JuliusBrussee/caveman` (MIT) — vendored copy, upstream pin TBD |
 | `find-skills` | `adapted-from: vercel-labs/skills` (MIT) — vendored copy, upstream pin TBD |
+| `grilling`, `grill-me`, `grill-with-docs` | `adapted-from: mattpocock/skills @ 84fdeffd` (MIT) |
 | all other `skills/*` | `author: ours` |
 
 Adaptation policy: a clone is rewritten to our conventions (`.tasks/` boards,