dev to staging

[thomashebrard]

Summary by cubic

Deprecates the legacy build and assemble endpoints, adds a new API version route, and updates docs to the unified /api/v1 interface and plural mthds_contents inputs. Upgrades pipelex to 0.22.0 and switches mthds to the PyPI release.

• Migration

  • Removed: POST /api/v1/build/pipe and POST /api/v1/assemble.
  • Field rename: mthds_content → mthds_contents (list of strings) across execute/start/validate/build.
  • Paths standardized under /api/v1 in docs; ensure clients use these routes.
  • Builder scope now: build/inputs, build/output, build/runner (no pipeline-from-brief endpoint).

• Dependencies

  • pipelex → 0.22.0 (from dev branch).
  • mthds → 0.2.0 from PyPI (was git source).

^{Written for commit 4a04599. Summary will update on new commits.}