chore: stop vendoring agent skills, point at upstream

[jamesbroadhead]

Narrowed in response to @andrelandgraf's feedback (#103 (comment)).

Summary

devhub's vendored skills aren't customer-facing — they're for the devhub team's own development. Most of them are close enough to their upstream sources to keep vendored. This PR now removes only the four most-divergent forks; everything else stays in place.

Removed (4)

Skill	Why	Upstream
databricks-apps	Missing State Storage Rule, Data Access Decision Gate, Genie / Model Serving routing, AppKit version + TypeScript cast guidance, smoke test selector rules. ~29% line drift but structurally far behind.	databricks/databricks-agent-skills
databricks-jobs	189 lines vs 409 upstream (54% drift).	databricks/databricks-agent-skills
databricks-lakebase	182 lines vs 315 upstream (42% drift).	databricks/databricks-agent-skills
databricks (legacy combined CLI / data / bundles skill)	No clean upstream counterpart — upstream split this into databricks-core + databricks-dabs.	databricks/databricks-agent-skills

Kept (11)

databricks-core, databricks-pipelines, agent-browser, building-components, deploy-to-vercel, frontend-design, mcp-builder, seo-audit, shadcn, vercel-cli, vercel-composition-patterns — all close enough to upstream that the maintenance cost of keeping them in-tree is low, and shipping them vendored means a fresh clone has the workflow skills ready without extra setup.

The two devhub-only skills (author-recipes-and-cookbooks, resource-image-generator) stay in-tree as before.

Agent-confusion mitigation

The original motivation included a concern that agents misread vendored skills as something devhub exposes to customers. That's now mitigated upstream by vercel-labs/skills#1281, which makes the install tooling ignore nested vendored skills.

Test plan

• npm run typecheck passes
• prettier -c AGENTS.md skills-lock.json clean
• Diff scope: 25 files, 13 insertions, 4468 deletions (was 171 files / 26393 deletions in the previous revision of this PR)

This pull request and its description were written by Claude (james.broadhead@databricks.com).

[andrelandgraf]

Let's hold off on merging this. These skills and AGENTS.md are not for our customers but for our own development of devhub. I understand the concern is that agents misunderstand these skills for being exposed by devhub. Hope this PR can help here vercel-labs/skills#1281

[jamesbroadhead]

Hi @andrelandgraf — Claude here, on James's behalf.

Reworked: narrowed this PR to only remove the most-drifted vendored skills (see updated description for the list), kept the rest in place. Given my timeline, I won't be able to iterate on this — this seems like a better compromise between modernising and consolidating vs forking/diverging. vercel-labs/skills#1281 covers the agent-confusion side for whatever stays vendored.

Up to you on whether to land it.

[andrelandgraf]

@thisistonydang can you just update the databricks agent skills in this repo to match latest from agent-skills repo? We should just do that as often as possible. Those skills help us author better content. But if it's confusing for agents (I'm unsure about that assumption) then we can also just remove them.