refactor: decompose monolithic profiler functions into focused helpers

[hhzhang16]

Overview:

Splits run_rapid, run_thorough, and run_profile into helper functions (one per logical stage), making each stage independently readable and testable. Adds tests for these helper functions.

Also simplifies the enumerate_profiling_configs in thorough.py and strips default-valued fields from the profiler test configs.

Details:

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Related Issues: (use one of the action keywords Closes / Fixes / Resolves / Relates to)

• closes GitHub issue: #xxx

[tedzhouhk]

test failed with

dgdr = DynamoGraphDeploymentRequestSpec(model='Qwen/Qwen3-32B', backend=<BackendType.Trtllm: 'trtllm'>, image='nvcr.io/nvidia..._metric_samples=10, load_min_observations=5), mocker=MockerSpec(enabled=True)), searchStrategy='rapid', autoApply=True)

    def _extract_profiler_params(dgdr: DynamoGraphDeploymentRequestSpec) -> tuple:
        """Pull all profiler parameters from dgdr and log them."""
        model = dgdr.model
        backend = dgdr.backend.value.lower()
        system = dgdr.hardware.gpuSku.lower()
        total_gpus = dgdr.hardware.totalGpus
        isl = dgdr.workload.isl
        osl = dgdr.workload.osl
        request_latency = dgdr.sla.e2eLatency
        if request_latency is not None:
            target_ttft = request_latency
            target_tpot = request_latency
        else:
            target_ttft = dgdr.sla.ttft
            target_tpot = dgdr.sla.itl
>       search_strategy = SearchStrategy(dgdr.searchStrategy.value)
                                         ^^^^^^^^^^^^^^^^^^^^^^^^^
E       AttributeError: 'str' object has no attribute 'value'

backend    = 'trtllm'
dgdr       = DynamoGraphDeploymentRequestSpec(model='Qwen/Qwen3-32B', backend=<BackendType.Trtllm: 'trtllm'>, image='nvcr.io/nvidia..._metric_samples=10, load_min_observations=5), mocker=MockerSpec(enabled=True)), searchStrategy='rapid', autoApply=True)
isl        = 4000
model      = 'Qwen/Qwen3-32B'
osl        = 1000
request_latency = None
system     = 'h200_sxm'
target_tpot = 50.0
target_ttft = 2000
total_gpus = 8

components/src/dynamo/profiler/profile_sla.py:67: AttributeError

because default needs to be SearchStrategy.Rapid

searchStrategy: SearchStrategy = Field(
        default="rapid",
        description='SearchStrategy controls the profiling search depth. "rapid" performs a fast sweep; "thorough" explores more configurations.',
    )