feat(tasks): bundle local skills into sha256-verified zip artifacts

[tatoalo]

Problem

for cloud tasks, local skill invocations only sent the slash command text. User-local and repo-local skills were available in the local editor but not in the cloud sandbox

Changes

• let's bundle uploadable local skills into zip artifacts with SHA-256 metadata and send them through the existing cloud artifact upload flow.

• install skill_bundle artifacts in the agent server before prompt delivery, inject the bundled skill instructions for the invoked turn, and suppress the raw slash command from the model-facing prompt so local skills behave like actual skills rather than unsupported commands

• refresh slash command metadata when a follow-up command is submitted, so newly created local skills can be selected and invoked without starting a brand-new task.

closes https://github.com/PostHog/code/issues/2260

[tatoalo]

• feat(tasks): surface local skills in the composer and upload on send #2926
• feat(tasks): route local skill tags through the cloud prompt pipeline #2925
• feat(tasks): install and apply skill bundle artifacts in the sandbox #2924
• feat(tasks): bundle local skills into sha256-verified zip artifacts #2923 👈 (View in Graphite)
• feat(tasks): add skill bundle artifact contracts and metadata types #2922
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[github-actions]

React Doctor found no issues in the changed files. 🎉

_{Reviewed by React Doctor for commit e8dec75.}

[greptile-apps]

_{Reviews (1): Last reviewed commit: "feat(tasks): bundle local skills into sh..." | Re-trigger Greptile}

[greptile-apps]

Security Review

• Arbitrary filesystem read via unguarded skillPath (packages/workspace-server/src/services/skills/skills.ts): The new bundleLocalSkill method omits the resolveKnownSkillDir check that every other skill-path consumer in the file applies. This check is the documented defense against turning the endpoint into an arbitrary filesystem read. Any caller who can reach the tRPC port can provide any path that contains a SKILL.md and receive the full directory contents as a base64-encoded zip.

_{Reviews (2): Last reviewed commit: "feat(tasks): bundle local skills into sh..." | Re-trigger Greptile}

[graphite-app]

Merge activity

• Jun 29, 2:37 PM UTC: Graphite disabled "merge when ready" on this PR due to: unsigned commits detected.