docs: Add Kubeflow Pipeline components documentation

[Copilot]

Description

Documents the Kubeflow Pipeline components (push-modelkit and unpack-modelkit) introduced in #1033.

New documentation page (docs/src/docs/integrations/kubeflow.md):

• Component reference for push-modelkit (packages and pushes ModelKits) and unpack-modelkit (pulls and extracts ModelKits)
• Complete example link positioned at the top for quick access
• Registry authentication and Cosign signing setup explained before code examples
• Focused code examples showing only KitOps-specific component definitions and usage
• Configuration guide for custom Kitfiles

Documentation structure:

• Prerequisites and complete example reference appear first
• Authentication setup (registry and optional Cosign) explained before usage
• Component specifications with inputs/outputs clearly defined
• Simplified code examples focused on KitOps integration (full pipeline code removed)
• Sections for custom Kitfiles and unpacking ModelKits
• Troubleshooting, Next Steps, and attestation metadata sections removed for simplicity

Integration updates:

• Added Kubeflow Pipelines to sidebar navigation in VitePress config
• Updated integrations index to reference new documentation

Build fix:

• Fixed dead link in documentation (changed ../deploy/ to ../deploy)

Example usage:

from kfp import dsl, kubernetes

@dsl.container_component
def push_modelkit(
    registry: str,
    repository: str, 
    tag: str,
    input_modelkit_dir: dsl.Input[dsl.Artifact],
    output_ref: dsl.Output[dsl.Artifact],
    output_digest: dsl.Output[dsl.Artifact],
):
    return dsl.ContainerSpec(
        image='ghcr.io/kitops-ml/kitops-kubeflow:latest',
        command=['/bin/bash', '-c'],
        args=[f'/scripts/push-modelkit.sh "{registry}" "{repository}" "{tag}" ...']
    )

# Use in pipeline after training
push = push_modelkit(
    registry='jozu.ml',
    repository='team/model',
    tag='latest',
    input_modelkit_dir=train.outputs['modelkit_dir'],
)

kubernetes.use_secret_as_volume(
    push,
    secret_name='docker-config',
    mount_path='/home/user/.docker',
)

Linked issues

Closes #1034

AI-Assisted Code

• This PR contains AI-generated code that I have reviewed and tested
• I take full responsibility for all code in this PR, regardless of how it was created

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Update the documentation for kubeflow component</issue_title>
<issue_description>Update the user documentation to refer to components created by #1033</issue_description>

Comments on the Issue (you are @copilot in this section)

Custom agent used: user-documentation-agent
Updates user-facing documentation based on code changes in PRs.

• Fixes Update the documentation for kubeflow component #1061

---

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View logs

[gorkem]

@copilot fix the failing build

[Copilot]

@copilot fix the failing build

Fixed the build error. The issue was a dead link in the Kubeflow documentation - changed ../deploy/ to ../deploy to properly reference the deploy.md file.

Commit: 5bca7ac

@copilot fix the failing build

Fixed in commit 5bca7ac. The build was failing due to a dead link - changed ../deploy/ to ../deploy in the Kubeflow documentation.

[gorkem]

@copilot Remove the "Troubleshooting" and "Next Steps" sections

[Copilot]

@copilot Remove the "Troubleshooting" and "Next Steps" sections

Removed both sections in commit 5eee305.

[bmicklea]

@copilot please make the following changes:

1. Bring the Complete Example section further up the page - it should be near the top and before all the inline code.
2. Explain how to use Authentication and Cosign before using those in code (currently they're each shown in code, then explained after)
3. Rather than including full code for the KubeFlow pipeline - focus code boxes on the chunks that are needed for KitOps

[gorkem]

@copilot please make the following changes:

1. Bring the Complete Example section further up the page - it should be near the top and before all the inline code.
2. Explain how to use Authentication and Cosign before using those in code (currently they're each shown in code, then explained after)
3. Rather than including full code for the KubeFlow pipeline - focus code boxes on the chunks that are needed for KitOps

[Copilot]

@copilot please make the following changes:

1. Bring the Complete Example section further up the page - it should be near the top and before all the inline code.
   ...

Done in commit 274ac8b. Changes made:

1. Moved Complete Example section to top (after Prerequisites, before all code)
2. Moved Registry Authentication and Cosign Signing sections before code examples that use them
3. Simplified all code examples to show only KitOps-specific component definitions and usage, removing full pipeline code

@copilot please make the following changes:

1. Bring the Complete Example section further up the page - it should be near the top and before all the inline code.
2. Explain how to use Authentication...

Done in commit 274ac8b. Changes made:

1. Moved Complete Example section to top (after Prerequisites, before all code)
2. Moved Registry Authentication and Cosign Signing sections before code examples that use them
3. Simplified all code examples to show only KitOps-specific component definitions and usage, removing full pipeline code

[gorkem]

@copilot remove the "Adding Attestation Metadata" section

[Copilot]

@copilot remove the "Adding Attestation Metadata" section

Removed in commit 63ec8d3.

[bmicklea]

LGTM