chore(linter): add new kube-api-linter and fix CRD lint issues

[dongjiang1989]

Add the kube-api-linter custom golangci-lint plugin to enforce Kubernetes API conventions across CRD type definitions. The following sub-linters are now enabled:

• nodurations — disallows time.Duration fields in API types (use string-based durations)
• noreferences — prevents use of pointer/reference types in API fields
• notimestamp — disallows time.Time fields in API types
• jsontags — ensures JSON struct tags follow Go naming conventions (lowercase first letter)
• statusoptional — enforces // +optional marker on status subfields

All resulting lint violations across v1alpha1 and v1alpha2 CRD types have been resolved. Most fixes involve lowercasing the first letter of JSON struct tags for compliance.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

This PR updates Kubernetes API type documentation and linter configuration to satisfy newly enabled kubeapilinter checks in Go.

Changes:

• Enabled additional kubeapilinter checks (e.g., jsontags, nomaps, notimestamp, nodurations) in golangci-lint config.
• Reworded many field doc comments to start with the JSON tag name (lowerCamel) rather than the Go field name.
• Added //nolint:kubeapilinter suppressions for a few fields in deprecated / soon-to-change APIs.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
go/api/v1alpha2/remotemcpserver_types.go	Adjusts CRD field docstrings and adds kubeapilinter suppressions for duration fields.
go/api/v1alpha2/modelproviderconfig_types.go	Updates field docstrings to match JSON tag names.
go/api/v1alpha2/modelconfig_types.go	Updates field docstrings to match JSON tag names across multiple config structs.
go/api/v1alpha2/common_types.go	Updates AllowedNamespaces field docstrings to match JSON tag names.
go/api/v1alpha2/agentharness_types.go	Updates many docstrings to match JSON tag names.
go/api/v1alpha2/agent_types.go	Updates many docstrings to match JSON tag names.
go/api/v1alpha1/toolserver_types.go	Adds kubeapilinter suppressions for deprecated API fields.
go/api/v1alpha1/modelconfig_types.go	Updates docstrings to match JSON tag names.
go/api/v1alpha1/agent_types.go	Updates A2AConfig docstring to match JSON tag name.
go/.golangci.yaml	Enables additional kubeapilinter checks.

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[dongjiang1989]

@EItanya PTAL, thanks