[BUG][Java][Spring] Mark HTTP interface configurators as @Generated

[axelray-dev]

Add the @Generated annotation to HttpInterfacesAbstractConfigurator for both Spring HTTP interface configurator variants.

PR checklist

• Read the contribution guidelines.
• Added regression coverage for both generated configurator variants.
• Focused SpringCodegen regression test: 1 test, 0 failures.
• Full project build, sample regeneration, and documentation export were not run locally.

Fixes #25121

---

Summary by cubic

Marks Spring HTTP interface configurators as @Generated so generated configurator classes are no longer flagged as hand-written, fixing #25121.

• Applies @Generated to both the default and HttpServiceProxyFactory configurator templates.
• Adds regression coverage for both variants and updates the related samples.
• Refreshes the nullable Go union sample docs pulled in when merging master.

^{Written for commit eb895c2. Summary will update on new commits.}

[axelray-dev]

The samples job was failing on the generated @generated annotation in the nine Spring HTTP-interface Petstore configurations. I regenerated those outputs with bin/generate-samples.sh; the focused SpringCodegenTest passes (1/1), and git diff --check is clean.

[cubic-dev-ai]

No issues found across 12 files

_{Re-trigger cubic}

[cubic-dev-ai]

1 issue found across 1 file (changes from recent commits).

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. When an issue isn't valid or won't be fixed in this PR, reply in its thread with the reason and then resolve the thread. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="samples/client/others/go/oneof-not-enum/docs/EnumNullUnion.md">

<violation number="1" location="samples/client/others/go/oneof-not-enum/docs/EnumNullUnion.md:7">
P2: `EnumNullUnion` is a oneOf wrapper, not a model with a `Kind` property; the generated type contains only `NullableEnum` and `NullableExcludedEnum`. The added property and `SetKindNil`/`UnsetKind` entries document APIs that do not exist on this type; document the union alternatives instead.</violation>
</file>

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>

[cubic-dev-ai]

P2: EnumNullUnion is a oneOf wrapper, not a model with a Kind property; the generated type contains only NullableEnum and NullableExcludedEnum. The added property and SetKindNil/UnsetKind entries document APIs that do not exist on this type; document the union alternatives instead.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. When an issue isn't valid or won't be fixed in this PR, reply in its thread with the reason and then resolve the thread. At samples/client/others/go/oneof-not-enum/docs/EnumNullUnion.md, line 7:

<comment>`EnumNullUnion` is a oneOf wrapper, not a model with a `Kind` property; the generated type contains only `NullableEnum` and `NullableExcludedEnum`. The added property and `SetKindNil`/`UnsetKind` entries document APIs that do not exist on this type; document the union alternatives instead.</comment>

<file context>
@@ -4,7 +4,7 @@
 Name | Type | Description | Notes
 ------------ | ------------- | ------------- | -------------
-**Kind** | Pointer to **string** |  | [optional] 
+**Kind** | Pointer to **NullableString** |  | [optional] 
 
 ## Methods
</file context>