Swap the unconditional `pnpm --filter @paperclipai/plugin-sdk build`
prebuild step for the idempotent `ensure-build-deps` script in three
CI entrypoints: `typecheck:build-gaps`, `test:run:general`, and
`test:run:serialized`.
`ensure-build-deps` produces the same shared+plugin-sdk dist outputs
but skips work when outputs already exist and uses a lockfile so
concurrent invocations within a job collapse into one build. On a
clean runner it is also slightly faster because it skips the nested
pnpm filter overhead and runs tsc directly with the package tsconfigs.
Plugin/example packages continue to call `ensure-build-deps` themselves
from their own prebuild/typecheck scripts, so clean-runner guarantees
are preserved.
Refs PAPA-339.
Co-Authored-By: Paperclip <noreply@paperclip.ing>
