Make paper training presets explicit

Co-Authored-By: PI[openai-codex] <288921227+claudypoo@users.noreply.github.com>

tests/test_config_presets.py

@@ -0,0 +1,41 @@
+from antipasto.config import default_configs
+from antipasto.train.train_adapter import is_optimizer_step, optimizer_steps_per_epoch
+
+
+def test_paper_v5_gemma1b_preset_matches_reported_hyperparameters():
+    config = default_configs["paper-v5-gemma1b-24gb"][1]
+
+    assert config.model_name == "google/gemma-3-1b-it"
+    assert config.seed == config.data_seed == 42
+    assert config.max_samples == 800
+    assert config.bs == 8
+    assert config.effective_bs == 32
+    assert config.n_epochs == 30
+    assert config.lr == 1e-3
+    assert config.wd == 1e-5
+    assert config.r == 128
+    assert config.n_modules == 64
+    assert config.warmup_pct == 0.3
+    assert config.mono_warmup_frac == 0.5
+    assert config.loss_subspace_rank == 8
+    assert config.loss_layer_frac == 0.9
+    assert config.min_adapter_layer_frac == 0.1
+
+
+def test_gemma270m_24gb_preset():
+    config = default_configs["gemma270m-24gb"][1]
+
+    assert config.model_name == "google/gemma-3-270m-it"
+    assert config.bs == 24
+
+
+def test_optimizer_steps_include_final_partial_accumulation():
+    updates = [
+        batch_idx
+        for batch_idx in range(85)
+        if is_optimizer_step(batch_idx, n_batches=85, grad_accum_steps=4)
+    ]
+
+    assert updates[-1] == 84
+    assert len(updates) == optimizer_steps_per_epoch(n_batches=85, grad_accum_steps=4) == 22
+    assert optimizer_steps_per_epoch(n_batches=84, grad_accum_steps=4) == 21