fix: propagate required flag to @RequestHeader-derived headers

[tangcent]

Summary

Fixes #1440: header parameters declared with @RequestHeader were exported through a
dedicated extractParamHeaders branch that built ApiHeader without consulting the
param.required rule. As a result headers always carried required = false and YApi
req_headers[].required was always 0, even when the rule resolved to true.

Changes

• Spring MVC (SpringMvcClassExporter): param.required now wins when configured;
  when no rule is set, the Spring default is applied in code — @RequestHeader is
  required unless required = false is declared explicitly.
• JAX-RS (JaxRsClassExporter) and custom framework (CustomClassExporter):
  param.required is now honoured for header-bound parameters (previously always
  emitted required = false).
• Rule engine: added RuleEngine.evaluateOrNull and
  DocMetadataResolver.resolveParamRequired so a framework-specific default can be
  applied only when no rule is configured.
• YApi (req_headers[].required) and OpenAPI (header.required) consumers now see the
  correct flag.

Tests

• SpringMvcRequestHeaderRequiredTest — covers the Spring default (no rules), the
  exact custom rule from the report, and rule-overrides-default precedence.
• JaxRsHeaderRequiredTest — covers rule-driven required propagation for @HeaderParam.
• YapiFormatterTest — added a contract test for the req_headers[].required mapping.

All new tests pass and the com.itangcent.easyapi.framework.* package is green. The
full suite could not be completed on this machine because the test executor JVM runs
out of native memory (pre-existing environment limitation, unrelated to this change).

Notes

• Without a param.required rule, @RequestParam (query params) keeps its current
  behaviour (optional). Aligning @RequestParam with the Spring default would be a
  separate, broader change.
• The header name for a parameter without a param.name rule still falls back to the
  Java parameter name rather than the @RequestHeader value — pre-existing behaviour,
  out of scope here.

[github-actions]

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• easy-yapi-3.2.3.221.251.zip — IntelliJ IDEA 2022.1 – 2025.1 (best-effort, not verified on older IDEs)

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[codecov]

Codecov Report

❌ Patch coverage is 80.76923% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 66.834%. Comparing base (62e3097) to head (a1a127f).

Files with missing lines	Patch %	Lines
...yapi/framework/springmvc/SpringMvcClassExporter.kt	76.923%	1 Missing and 2 partials ⚠️
...nt/easyapi/framework/custom/CustomClassExporter.kt	80.000%	0 Missing and 1 partial ⚠️
...cent/easyapi/framework/jaxrs/JaxRsClassExporter.kt	80.000%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@              Coverage Diff              @@
##            master     #1441       +/-   ##
=============================================
+ Coverage   66.805%   66.834%   +0.028%     
=============================================
  Files          468       468               
  Lines        27146     27169       +23     
  Branches      6520      6522        +2     
=============================================
+ Hits         18135     18158       +23     
  Misses        6544      6544               
  Partials      2467      2467               

Flag	Coverage Δ
unittests	66.834% <80.769%> (+0.028%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...ent/easyapi/core/psi/helper/DocMetadataResolver.kt	73.737% <100.000%> (+0.268%)	⬆️
...m/itangcent/easyapi/core/rule/engine/RuleEngine.kt	73.214% <100.000%> (+0.487%)	⬆️
...nt/easyapi/framework/custom/CustomClassExporter.kt	79.638% <80.000%> (+0.375%)	⬆️
...cent/easyapi/framework/jaxrs/JaxRsClassExporter.kt	85.075% <80.000%> (+0.459%)	⬆️
...yapi/framework/springmvc/SpringMvcClassExporter.kt	84.898% <76.923%> (-0.081%)	⬇️

... and 1 file with indirect coverage changes

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[github-actions]

📦 Plugin has been packaged for this PR. You can download it from the GitHub Actions workflow run by clicking on the "Artifacts" dropdown:

• easy-yapi-3.2.3.252.0.zip — IntelliJ IDEA 2025.2+ (officially supported)
• easy-yapi-3.2.3.221.251.zip — IntelliJ IDEA 2022.1 – 2025.1 (best-effort, not verified on older IDEs)

Each artifact is a ready-to-install plugin zip — pick the one matching your IDEA version and install it via Settings → Plugins → ⚙ → Install Plugin from Disk. No extraction needed.

[bobexchen]

Confirmed working. I installed the artifact build (easy-yapi-3.2.3.252.0.zip) and exported to YApi again — req_headers[].required now correctly reflects the @RequestHeader#required attribute:

• @RequestHeader("x-user-id") → required: 1
• @RequestHeader(value = "x-timezone-id", required = false) → required: 0

Thanks for the quick fix! Looking forward to the next release.