feat!: replace root module with the black-box SDK test harness

[kpenfound]

What

Replaces the root sdk-sdk module with the black-box SDK test harness, carrying forward the still-useful tooling from the previous root module. The root module does it all:

dagger -m github.com/dagger/sdk-sdk -W <sdk-repo> check

Lifecycle checks

The checks vendor the SDK module into a scratch git workspace inside a runner container (pinned, checksum-verified release CLI, default 1.0.0-beta.9) and drive it the way a user would:

• dagger sdk install ./<sdk> succeeds and records the as-sdk marker
• dagger module init <sdk> test-mod scaffolds the module, writes dagger-module.toml, installs it in dagger.toml, and records the authoring-SDK entry
• dagger generate succeeds on the fresh scaffold, and is anchored at the caller's cwd (generate from inside one module's directory leaves a sibling module untouched)
• the scaffolded module loads and serves its API (dagger api functions — templates may expose no functions yet)
• dagger sdk module-options introspects initModule
• dagger module engine required / dagger module deps list work from the module directory

Each lifecycle stage and each contract behavior is its own check; when a stage fails, dependent checks report a prerequisite command failed message naming that stage instead of repeating raw errors.

Carried forward from the old root module

• initModule + init-template/ + helpers/render-init-template/ — sdk-sdk is still the SDK for authoring new Dang SDK helper modules (dagger module init sdk-sdk my-sdk)
• The function-level contract checks (changeset hygiene), aligned with how the engine drives SDKs: explicit --path, @generate hook detected via dagger generate -l

Self-hosting instead of fixtures

sdk-sdk fulfills its own SDK contract (targetRuntime, initModule, a no-op @generate), so dagger check in this repo runs every check against sdk-sdk itself.

Housekeeping

• Root config is dagger-module.toml (engineVersion v1.0.0-0) plus a dagger.toml workspace config
• ./polyfill deleted in favor of github.com/dagger/polyfill; mod-test cut over to dagger api call -j

Verification (released v1.0.0-beta.9 CLI + engine)

• In-repo dagger check: 22/22
• go-sdk main: 19/19
• dang-sdk main: 19/19
• typescript-sdk main: 19/19
• python-sdk main: 19/19

🤖 Generated with Claude Code

[TomChv]

We should add a part to test client generation, but that should only enabled through a setting because some SDK doesn't support client gen yet.
I think that could be done in a follow up though

[TomChv]

Do you think you could take care of dagger/dagger#13688 as part of the changes since you remove a lot of the modules? Do we even need that now?

[kpenfound]

New list of functions in the sdk-sdk:

Name                                                 Type       Description
sdk-sdk:deps-list-succeeds                           check      `dagger module deps list` should succeed for a scaffolded module.
sdk-sdk:engine-required-reports-version              check      `dagger module engine required` should report a version for a scaffolded module.
sdk-sdk:generate-exposes-generator                   check      An SDK module should expose a `@generate` hook.
sdk-sdk:generate-respects-cwd                        check      `dagger generate` should be anchored at the caller's cwd.
sdk-sdk:generate-succeeds                            check      `dagger generate` should succeed on a freshly scaffolded module.
sdk-sdk:init-module-does-not-remove-existing-files   check      `initModule` should not remove existing files when creating a new module.
sdk-sdk:init-module-does-not-write-config            check      `initModule` should not write engine-owned config files.
sdk-sdk:init-module-honors-custom-path               check      `initModule --path` should stage files under the requested path.
sdk-sdk:init-module-renders-root-type                check      sdk-sdk's own `initModule` should render CLI module names as a valid Dang root type.
sdk-sdk:init-module-seeds-files                      check      `initModule` should seed SDK files for a new module.
sdk-sdk:init-records-authoring-sdk                   check      `dagger module init` should record the SDK as the new module's authoring SDK.
sdk-sdk:init-registers-module                        check      `dagger module init` should install the new module in dagger.toml.
sdk-sdk:init-scaffolds-module                        check      `dagger module init <sdk> <name>` should scaffold a new module.
sdk-sdk:init-writes-module-config                    check      `dagger module init` should write the new module's dagger-module.toml.
sdk-sdk:install-marks-as-sdk                         check      `dagger sdk install` should mark the SDK with an as-sdk marker in dagger.toml.
sdk-sdk:install-registers-sdk                        check      `dagger sdk install` should accept the SDK module.
sdk-sdk:scaffolded-module-serves-functions           check      A scaffolded module should serve at least one function after `dagger generate`.
sdk-sdk:sdk-reports-module-options                   check      `dagger sdk module-options` should introspect the SDK's initModule capability.
sdk-sdk:generate                                     generate   Regenerate the modules this SDK manages.

[TomChv]

Tested on the typescript-sdk repo and it works as expected:

TRACE  ✔ PASSED
dagger-1.0.0-beta.9 -m github.com/dagger/sdk-sdk@sdk-test -W . check  1m9s

CHECKS  ✔ 19 passed
✔ sdk-sdk:deps-list-succeeds 1m3s OK
✔ sdk-sdk:engine-required-reports-version 1m3s OK
✔ sdk-sdk:generate 1.1s OK
✔ sdk-sdk:generate-exposes-generator 17.4s OK
✔ sdk-sdk:generate-respects-cwd 1m2s OK
✔ sdk-sdk:generate-succeeds 1m2s OK
✔ sdk-sdk:init-module-does-not-remove-existing-files 29.1s OK
✔ sdk-sdk:init-module-does-not-write-config 29.3s OK
✔ sdk-sdk:init-module-honors-custom-path 29.3s OK
✔ sdk-sdk:init-module-renders-root-type 16.0s OK
✔ sdk-sdk:init-module-seeds-files 29.1s OK
✔ sdk-sdk:init-records-authoring-sdk 29.5s OK
✔ sdk-sdk:init-registers-module 29.5s OK
✔ sdk-sdk:init-scaffolds-module 29.4s OK
✔ sdk-sdk:init-writes-module-config 29.5s OK
✔ sdk-sdk:install-marks-as-sdk 15.5s OK
✔ sdk-sdk:install-registers-sdk 15.5s OK
✔ sdk-sdk:scaffolded-module-loads 1m5s OK
✔ sdk-sdk:sdk-reports-module-options 17.4s OK