[Feature] Project model

[TorinAsakura]

Task

• Close [Feature] Project model #799

How to verify

Main scenario

1. Context: Raijin commands resolve a Yarn project from a single-project repository, a monorepo, or a nested workspace invocation.
   Action: sync, typecheck, and checks consume the project model from @atls/raijin/project.
   Expected result: every consumer uses the Yarn top-level workspace, normalized workspace definitions, and the same project type.

Additional scenario

1. Context: the project model previously lived in the legacy @atls/yarn-plugin-tools/project path.
   Action: build and pack @atls/raijin, rebuild the Yarn runtime, and import the packed @atls/raijin/project subpath from a clean npm consumer.
   Expected result: the packed public package contains dist/project, the clean import succeeds, and the replaced plugin-tools path and export are absent.

Proofs

• yarn test unit yarn/raijin/src/project/manifest/manifest.test.ts yarn/raijin/src/project/type/type.test.ts yarn/raijin/src/project/workspaces/workspaces.test.ts yarn/plugin-tools/sources/commands/sync/tsconfig.command.test.ts yarn/plugin-tools/sources/commands/sync/typescript.command.test.ts yarn/plugin-typescript/sources/typecheck.command.test.ts yarn/plugin-checks/sources/checks-typecheck.command.test.ts --test-reporter=tap
• targeted yarn typecheck and yarn lint for the project model and migrated consumers
• yarn workspace @atls/raijin build
• yarn workspace @atls/yarn-plugin-tools build
• yarn workspace @atls/yarn-plugin-typescript build
• yarn workspace @atls/yarn-plugin-checks build
• yarn workspace @atls/yarn-cli build
• cmp -s yarn/cli/dist/runtime/yarn.mjs .yarn/releases/yarn.mjs
• yarn workspace @atls/raijin pack --out /tmp/atls-raijin-pr812.tgz
• clean npm consumer import of packed @atls/raijin/project
• yarn raijin:check
• yarn check
• git diff --check -- ':!.yarn/releases/yarn.mjs'

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