feat(generator): build full SDK generation foundation

[nmorgan-cb]

Description

Builds the deterministic, OpenAPI-driven generation foundation for the full Coinbase Prime Java client surface.

Generator implementation included

• Uses committed apiSpec/prime-public-spec.yaml for normal generation and CI; live fetching is explicit only.
• Runs OpenAPI model/enum generation and the existing model post-processing before custom client-surface emission.
• Adds shared paths, configuration, naming/type resolution, request, response, service, factory, and template phases.
• Generates SDK-style mutable request/response DTOs, synchronous services/implementations, and PrimeServiceFactory deterministically.
• Supports path/version routing, including /v1 stripping, per-call /v2 base URLs, numeric 2xx statuses, and the documented 201/200 create/claim/submit compatibility rule.
• Adds manifest-backed reconciliation that only deletes previously owned files and protects the legacy portfolio counterparty compatibility artifacts.
• Adds make fetch-spec, make generate, make check-generated, and make generate-live-diff commands.

Tests added

• Adds focused fixture coverage for request/response/service/factory rendering, shared model/enum/array/map type resolution, deterministic service ordering, v2 validation, compatibility statuses, and manifest-safe stale cleanup.
• Extends parser handling so operation-level parameters correctly override same-name path-level declarations.

Generation preview performed

• Ran the full generator in a detached temporary worktree from the committed OpenAPI spec.
• The preview completed successfully and reported broad model/client-surface drift (434 tracked Java files; 19,945 insertions and 21,440 deletions), which is intentionally left for review as the generated baseline follow-up.

Generated SDK baseline intentionally not committed

No regenerated model, DTO, service, factory, or spec artifacts from the preview are included in this PR. Generated changes will be committed only after the generated baseline is reviewed.

Remaining follow-up

Review and commit the generated SDK baseline, then enable make check-generated as a required CI gate.

Generated with Toshi

Type of Change

• Bug fix
• New feature
• Breaking change
• Dependency update
• Refactor / cleanup
• Other (describe below)

Checklist

• Tests included / updated
• Changelog updated
• Version bump if needed

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1