Add WeatherNext-style ONNX conversion demo

[Copilot]

WeatherNext uses a JAX/Haiku + xarray architecture that does not map to the existing HuggingFace model registry flow. This PR adds a runnable ONNX demo that sketches the WeatherNext one-step forecast contract and graph workflow under examples/.

• Demo workflow

  • Adds examples/weathernext.py.
  • Builds a small deterministic grid→mesh→grid forecast graph.
  • Saves the result as a standard Mobius ModelPackage.
  • Supports optional ONNX Runtime validation with --validate.

• WeatherNext-style graph contract

  • Inputs:
    • input_state: weather variables on a lat/lon grid
    • forcings: known future forcing variables
    • sample_noise: stochastic FGN-style noise channels
  • Output:
    • next_state: one-step forecast grid

• Coverage

  • Adds tests/weathernext_example_test.py to verify the exported ONNX graph I/O contract.

Example:

PYTHONPATH=src python examples/weathernext.py output/weathernext-mini --validate

• Fixes Convert weather next #468

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✅ justinchuby
❌ Copilot
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[justinchuby]

@copilot what I wanted was a formal support of this model in the modeling/integation files, and a demo script that can run this model on real data.

[Copilot]

@copilot what I wanted was a formal support of this model in the modeling/integation files, and a demo script that can run this model on real data.

Implemented in f588c1a (with the WeatherNext support commits immediately before it): the WeatherNext graph is now formalized under mobius config/model/task/integration modules, and examples/weathernext.py uses that path with NPZ/xarray real-data inputs plus optional converted weights.

[justinchuby]

The advertised f16 validation path is currently not executable.

The requested f16 inference fix and regression test landed in 6156702; follow-up lint cleanup landed in f9191fd.

[github-actions]

Performance Comparison

Comparing 78437cd → f9191fd

Model	Metric	Baseline	Current	Delta
bert (feature-extraction)	model_size_bytes	359 KB	359 KB	+0.0%	⚪
bert (feature-extraction)	num_nodes	60	60	+0.0%	⚪
falcon	model_size_bytes	364 KB	364 KB	+0.0%	⚪
falcon	num_nodes	68	68	+0.0%	⚪
gemma2	model_size_bytes	428 KB	428 KB	+0.0%	⚪
gemma2	num_nodes	107	107	+0.0%	⚪
gpt2	model_size_bytes	388 KB	388 KB	+0.0%	⚪
gpt2	num_nodes	54	54	+0.0%	⚪
llama	model_size_bytes	425 KB	425 KB	+0.0%	⚪
llama	num_nodes	62	62	+0.0%	⚪
llama (static-cache)	model_size_bytes	425 KB	425 KB	+0.0%	⚪
llama (static-cache)	num_nodes	58	58	+0.0%	⚪
mamba (ssm-text-generation)	model_size_bytes	296 KB	296 KB	+0.0%	⚪
mamba (ssm-text-generation)	num_nodes	98	98	+0.0%	⚪
phi3	model_size_bytes	421 KB	421 KB	+0.0%	⚪
phi3	num_nodes	60	60	+0.0%	⚪
phi3 (static-cache)	model_size_bytes	421 KB	421 KB	+0.0%	⚪
phi3 (static-cache)	num_nodes	56	56	+0.0%	⚪
qwen2	model_size_bytes	425 KB	425 KB	+0.0%	⚪
qwen2	num_nodes	62	62	+0.0%	⚪
qwen2 (static-cache)	model_size_bytes	425 KB	425 KB	+0.0%	⚪
qwen2 (static-cache)	num_nodes	58	58	+0.0%	⚪
qwen3_5_moe (hybrid-text-generation)	model_size_bytes	506 KB	506 KB	+0.0%	⚪
qwen3_5_moe (hybrid-text-generation)	num_nodes	275	275	+0.0%	⚪
qwen3_5_text (hybrid-text-generation)	model_size_bytes	458 KB	458 KB	+0.0%	⚪
qwen3_5_text (hybrid-text-generation)	num_nodes	129	129	+0.0%	⚪
qwen3_5_vl (hybrid-qwen-vl)	model_size_bytes	977 KB	977 KB	+0.0%	⚪
qwen3_5_vl (hybrid-qwen-vl)	num_nodes	431	431	+0.0%	⚪
t5 (seq2seq)	model_size_bytes	836 KB	836 KB	+0.0%	⚪
t5 (seq2seq)	num_nodes	166	166	+0.0%	⚪
whisper (speech-to-text)	model_size_bytes	1008 KB	1008 KB	+0.0%	⚪
whisper (speech-to-text)	num_nodes	128	128	+0.0%	⚪

No performance regressions.

[github-actions]

🏗️ Architecture Diff

Comparing 78437cd → f9191fd

Model	Sub-model	Changes	Status
bert (feature-extraction)	model	0	⚪
falcon	model	0	⚪
gemma2	model	0	⚪
gemma4 (gemma4)	decoder	0	⚪
gemma4 (gemma4)	embedding	0	⚪
gemma4 (gemma4)	vision_encoder	0	⚪
gemma4_text	model	0	⚪
gpt2	model	0	⚪
llama	model	0	⚪
llama (static-cache)	model	0	⚪
mamba (ssm-text-generation)	model	0	⚪
phi3	model	0	⚪
phi3 (static-cache)	model	0	⚪
qwen	model	0	⚪
qwen (static-cache)	model	0	⚪
qwen2	model	0	⚪
qwen2 (static-cache)	model	0	⚪
qwen2_moe	model	0	⚪
qwen2_moe (static-cache)	model	0	⚪
qwen3	model	0	⚪
qwen3 (static-cache)	model	0	⚪
qwen3_5_moe (hybrid-text-generation)	model	0	⚪
qwen3_5_text (hybrid-text-generation)	model	0	⚪
qwen3_5_vl (hybrid-qwen-vl)	decoder	0	⚪
qwen3_5_vl (hybrid-qwen-vl)	embedding	0	⚪
qwen3_5_vl (hybrid-qwen-vl)	vision_encoder	0	⚪
qwen3_moe	model	0	⚪
qwen3_moe (static-cache)	model	0	⚪
qwen3_next (hybrid-text-generation)	model	0	⚪
t5 (seq2seq)	decoder	0	⚪
t5 (seq2seq)	encoder	0	⚪
whisper (speech-to-text)	decoder	0	⚪
whisper (speech-to-text)	encoder	0	⚪

No architecture changes detected. ✅

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Legend: ⚪ No change · 🔵 Minor (attrs/inits) · 🟡 Moderate (nodes added/removed) · 🔴 Major (interface changed)