_check_unavailable_skill is meant to turn a typed "/foo" command that
doesn't resolve into a specific hint — "disabled, enable with hermes
skills config" or "available but not installed, install with hermes
skills install …" — instead of the generic "unknown command" reply.
It was doing the match with `skill_md.parent.name.lower().replace("_", "-")`,
comparing that to the typed command. For every skill whose directory name
drifted from its declared frontmatter `name:`, that comparison failed and
the user got the unhelpful generic path. On a standard install today 19
skills have this drift, e.g.:
dir: mlops/stable-diffusion
frontmatter: name: Stable Diffusion Image Generation
registered slug (what the user types): /stable-diffusion-image-generation
dir: mlops/qdrant
frontmatter: name: Qdrant Vector Search
registered slug: /qdrant-vector-search
dir: mlops/flash-attention
frontmatter: name: Optimizing Attention Flash
registered slug: /optimizing-attention-flash
In every case, _check_unavailable_skill would fall through because
"stable-diffusion" != "stable-diffusion-image-generation", even with the
skill sitting right there on disk.
Fix: extract a small `_skill_slug_from_frontmatter` helper that reads the
SKILL.md frontmatter and normalizes exactly like scan_skill_commands
(lower, spaces/underscores → hyphens, strip non-[a-z0-9-], collapse
runs of hyphens, strip edges). Use it in both the
disabled-skills branch and the optional-skills branch. The disabled-set
membership check now uses the declared frontmatter name (which is what
`hermes skills config` writes into skills.disabled / platform_disabled),
not the slug.
Tests: five cases in tests/gateway/test_unavailable_skill_hint.py —
the drift case for the disabled branch, unknown-command negative,
matched-but-not-disabled negative, non-alnum stripping, and the drift
case for the optional-skills branch. All five fail against main and
pass with the fix.
