fix(eve): support symlinked skill discovery

[iroiro147]

Summary

• resolve skill entries that appear as filesystem links before classifying authored skills
• support flat markdown skill symlinks, package directory symlinks, and packaged SKILL.md symlinks
• add disk-backed integration coverage and a patch changeset

Fixes #205.

Tests

• pnpm --filter eve run build:compiled
• pnpm --filter eve exec vitest run --config vitest.integration.config.ts src/discover/skills.integration.test.ts
• pnpm exec oxfmt --check packages/eve/src/discover/skills.ts packages/eve/src/discover/skills.integration.test.ts .changeset/skill-discovery-symlinks.md
• pnpm --filter eve exec oxlint src/discover/skills.ts src/discover/skills.integration.test.ts --deny-warnings
• pnpm --filter eve run typecheck
• pnpm guard:invariants
• pnpm changeset status --since origin/main
• git diff --check
• git diff --cached --check

[vercel]

@iroiro147 is attempting to deploy a commit to the Vercel Team on Vercel.

A member of the Team first needs to authorize it.

[iroiro147]

Rebased this onto current main and pushed signed head 7528916b. I also hardened compilation so linked skill packages are dereferenced into self-contained workspace resources and included in the resource hash, added a compile scenario that removes the original linked source before validating the artifact, made unsupported link creation an explicit skip, covered Windows junctions, and updated the skill-sharing docs. Verified under Node 24 with 8 discovery integration tests, the focused compile scenario, package typecheck, all documentation checks, invariant checks, and git diff --check. Fresh CI is running.