[v1]: Add v1 mirrors for unit tests

[Ratish1]

Motivation

I mirrored the non-Ming bucket-1 unit tests from #335 into the v1 test surface so Stage A v1 CI can protect the equivalent contracts while the v0 tests continue to protect the legacy stack during migration.

Modifications

• Added v1 mirrors for Qwen3 config, model path resolution, model worker port selection, OpenAI API behavior, registry config discovery, relay backends, stream queue behavior, and video preprocessing.
• Reworked scheduler coverage for the v1 architecture by testing Coordinator, SimpleScheduler, and OmniScheduler inbox/outbox contracts instead of porting v0 scheduler internals directly.
• Expanded v1 model-path coverage around preprocessor cache-key context, default context-length rejection, video-audio extraction cache keys, encoder cache reuse, encoder batch deduplication, image encoder cost accounting, and weight-loader refresh behavior.
• Did not mirror Ming tests in this PR. Ming coverage is left for the codeowners to transfer separately.
• Left test_mem_fraction_static.py as v0-only because v1 does not currently have the encoder_mem_reserve helper; v1 only has generic mem_fraction_static ServerArgs construction.

Bucket Checklist

Source test	Issue bucket	V1 status	PR action
test_cache_key.py	2	Stage B rewrite around v1 preprocessor cache-key functions	Pending Stage B
test_cli_version_dispatch.py	3	v0 shim only; existing v1 guard remains separate	v0-only
test_code2wav_executor.py	3	v1 code2wav is scheduler/inbox/outbox	v0-only
test_code_predictor_executor.py	3	v1 folds into model code predictor path	v0-only
test_direct_model_executor.py	3	no v1 DirectModelExecutor	v0-only
test_factory.py config slice	1	Qwen3OmniSpeechPipelineConfig and CLI override helpers; legacy TP rejection becomes v1 explicit GPU-list acceptance plus GPU-count mismatch rejection	tests/test_v1_qwen3_config.py
test_factory.py assembly slice	3	no v1 engines.omni.factory counterpart	v0-only
test_ipc_runtime_dir.py	2	v1 endpoint allocation changed	Pending Stage B
test_mem_fraction_static.py	3	no current v1 encoder_mem_reserve helper; v1 only has generic mem_fraction_static ServerArgs construction	v0-only
test_ming_architecture_resolution.py	Ming	codeowner transfer	Not mirrored
test_ming_config.py	Ming	codeowner transfer	Not mirrored
test_ming_tokenizer_loading.py	Ming	codeowner transfer	Not mirrored
test_ming_asr.py	4 / Ming	external server script	Not mirrored
test_ming_omni_talker.py	4 / Ming	real-weight smoke	Not mirrored
test_ming_omni_vision_e2e.py	4 / Ming	E2E	Not mirrored
test_ming_talker_concurrent.py	4 / Ming	benchmark script	Not mirrored
test_model_path_resolution.py preprocessor/weight/cache/cost groups	1	v1 preprocessor, request builders, encoder stage cache/cost helpers, weight loader	tests/test_v1_model_path_resolution.py
test_model_path_resolution.py encoder executor wiring	3	v0 executor layer only	v0-only
test_model_worker_ports.py	1	v1 model worker _resolve_nccl_port	tests/test_v1_model_worker_ports.py
test_omni_engine.py	3	no v1 engine factory counterpart	v0-only
test_openai_api.py	1	v1 OpenAI HTTP surface	tests/test_v1_openai_api.py
test_real_code2wav_parity.py	3	no v1 _forward_batch	v0-only
test_registry_import_pipeline_configs.py	1	v1 pipeline config discovery	tests/test_v1_registry_import_pipeline_configs.py
test_relay_unified.py	1	v1 relay backends	tests/test_v1_relay_unified.py
test_relay_unified_multiprocess.py	1	v1 relay multiprocess backends	tests/test_v1_relay_unified_multiprocess.py
test_s2pro_streaming.py	3	no v1 streaming vocoder helper layer	v0-only
test_scheduler.py	1	v1 Coordinator terminal completion and SimpleScheduler batch-cost contract	tests/test_v1_scheduler.py
test_scheduler_streaming.py	1	v1 stream chunk/done/abort handling	tests/test_v1_scheduler_streaming.py
test_stream_queue.py	1	v1 StreamQueue import retarget	tests/test_v1_stream_queue.py
test_talker_error_propagation.py Ming part	Ming	bcodeowner transfer	Not mirrored
test_talker_error_propagation.py Qwen3 part	3	v1 Qwen3 talker executor module gone	v0-only
test_tp_batch_serialization.py	3	v1 TP handled by native SGLang/stage processes	v0-only
test_tp_follower.py	3	v1 TP handled by native SGLang/stage processes	v0-only
test_tts_playground_client.py	2	Stage B client/audio retarget	Pending Stage B
test_tts_playground_streaming.py	2	Stage B client/audio retarget	Pending Stage B
test_tts_playground_ui.py	2	Stage B client/audio retarget	Pending Stage B
test_video_frontend.py	1	v1 preprocessing/video import retarget	tests/test_v1_video_frontend.py

Testing

v1 Tests PASSED