fix(opam): add pin-depends for ppx_forbid and dev-repo field

[vch9]

Summary

• Add pin-depends field to miaou-core.opam to automatically pin ppx_forbid from GitHub
• Add dev-repo field to all opam packages for better package metadata

Background

The ppx_forbid package was added as a build dependency in #118 but it's not available in the opam repository yet. This causes opam install . --deps-only --with-test to fail with:

[ERROR] Package conflict!
  * Missing dependency:
    - deps-of-miaou → deps-of-miaou-core → ppx_forbid
    unknown package

Changes

1. miaou-core.opam: Added pin-depends field to automatically pin ppx_forbid from https://github.com/atacama-dev/ppx_forbid.git
2. All *.opam files: Added dev-repo field pointing to the project repository

Testing

The pin-depends field works when:

• Installing from opam repository: opam install miaou
• Installing with opam pin: opam pin add miaou .

For local development with opam install ., users still need to manually pin:

opam pin add ppx_forbid https://github.com/atacama-dev/ppx_forbid.git -y
opam install . --deps-only --with-test -y

This is a limitation of opam's pin-depends field with local directory installs.

Note

The dev-repo field additions are standard opam package metadata that help users find the source repository.

[mathiasbourgoin]

LGTM, thanks for the nice contribution!