Fix ContentType ignoring enumStyle: "union" in http-client

[Upgrade220]

Problem

When enumStyle: "union" is configured, user-defined enums are generated as plain type aliases. The built-in ContentType in the http-client was not covered by this path — it fell through to the else branch and was always generated as a regular enum. This was overlooked in #1754 when enumStyle was introduced; only the const case was handled for ContentType.

Beyond the declaration, all call sites inside the http-client class body (contentFormatters, type || ContentType.Json, type !== ContentType.FormData) and in generated API methods (type: ContentType.Json) used dot-property access, which is invalid when ContentType is a type alias with no runtime object. This also causes isolatedModules errors in the modular output's import.

Fixes #1761.

Solution

• Adds a union branch to both fetch-http-client.ejs and axios-http-client.ejs that emits export type ContentType = "application/json" | ...
• Introduces templates/base/content-type-accessors.ejs, a shared partial (following the route-docs.ejs pattern) that returns the correct accessor string for each content type based on enumStyle. It serves two consumers with different key conventions: http-client templates use camelCase keys (CT.Json), procedure-call templates use UPPER_SNAKE keys (requestContentKind["JSON"]) matching the CONTENT_KIND constants from schema-routes.ts
• Updates modular/api.ejs to emit import { …, type ContentType, … } (inline type import) in union mode, avoiding isolatedModules errors
• Adds a union-enums-http-client test case to the existing enumStyle spec

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Summary by cubic

Makes ContentType in generated http-clients respect enumStyle: "union", fixing invalid property access and isolatedModules issues. Unifies content-type access across templates to work with both enum and union modes.

• Bug Fixes

  • Generate ContentType as a union type in fetch-http-client.ejs and axios-http-client.ejs when enumStyle is "union".
  • Use shared accessors via templates/base/content-type-accessors.ejs in http-clients and procedure-call templates to avoid dot-property access in union mode.
  • In modular builds, import type ContentType from the http-client when in union mode to satisfy isolatedModules.
  • Add union-enums-http-client test coverage.

• Migration

  • If you reference ContentType.* at runtime while using enumStyle: "union", switch to string literals (e.g., "application/json") or treat ContentType as a type-only import. No changes needed for generated API usage.

^{Written for commit 90cf9cc. Summary will update on new commits. Review in cubic}

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Latest commit: 90cf9cc

The changes in this PR will be included in the next version bump.

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swagger-typescript-api	Patch

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[cubic-dev-ai]

No issues found across 9 files

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