chore(trainer): add trainerclient and optimizerclient sections

[aniketpati1121]

• Added Client Entrypoints section for TrainerClient and OptimizerClient
• Updated Trainer Types: CustomTrainer, CustomTrainerContainer, BuiltinTrainer
• Added Backends, Training Options, Typical Flow, and Integration Patterns
• Updated Repository Map for clarity
  fixes Update AGENTS.md with OptimizerClient and new features #189

[google-oss-prow]

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[coveralls]

Pull Request Test Coverage Report for Build 21257997032

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

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Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 243 unchanged lines in 11 files lost coverage.
• Overall coverage increased (+0.9%) to 67.52%

---

Files with Coverage Reduction	New Missed Lines	%
kubeflow/optimizer/backends/base.py	2	0.0%
kubeflow/trainer/backends/base.py	3	71.43%
kubeflow/optimizer/api/optimizer_client.py	5	0.0%
kubeflow/trainer/types/types.py	7	96.17%
kubeflow/trainer/backends/kubernetes/backend_test.py	10	96.12%
kubeflow/trainer/api/trainer_client.py	12	69.05%
kubeflow/trainer/backends/localprocess/backend.py	25	73.17%
kubeflow/trainer/backends/kubernetes/backend.py	30	79.78%
kubeflow/trainer/backends/container/backend.py	31	78.5%
kubeflow/trainer/backends/kubernetes/utils.py	45	77.35%

Totals
Change from base Build 19937262845:	0.9%
Covered Lines:	2769
Relevant Lines:	4101

---

💛 - Coveralls

[Copilot]

Pull request overview

This PR enhances the documentation for the Trainer component by restructuring the content into clearer, more organized sections. The changes improve readability and provide better navigation for developers working with training workflows.

Changes:

• Reorganized Trainer documentation with clearer section headers and structure
• Added dedicated sections for Client Entrypoints, Backends, Training Options, Typical Flow, and Integration Patterns
• Expanded Trainer Types descriptions with better formatting and more detailed attribute listings
• Added a Repository Map section to help developers navigate the codebase

[Copilot]

The heading '## Components' is at the wrong level and is misleading. This section only describes the Trainer component, not multiple components. Since it follows 'Component: Trainer', this should either be removed or changed to '### Trainer Details' or similar to maintain proper hierarchy.

[Copilot]

The description states OptimizerClient is for 'optimization workflows such as hyperparameter tuning and performance optimization' but doesn't clarify how this differs from TrainerClient or when to use each. Consider adding a brief note about when to use OptimizerClient vs TrainerClient.

[andreyvelich]

I don't think we need to be too detailed here since agents can always read the code for additional context.

Similar to this PR, can you better improve the repository map which shows where to find TrainerClient APIs, OptimizerClient APIs, and ModelRegistry client API: kubeflow/trainer#3121