Clarify California scope and add CONUS retraining recipe

training/configs/train_firewx_fm_conus_seed7_template.json

@@ -0,0 +1,52 @@
+{
+  "index_root": "/path/to/local/firewx_fm_cache/conus_hrrr_us_5km_l12",
+  "run_root": "/path/to/local/firewx_fm_runs",
+  "tile_size": 32,
+  "max_positive_tiles_per_sample": 96,
+  "min_negative_tiles_per_sample": 8,
+  "negative_to_positive_ratio": 3.0,
+  "positive_rate_source": "tiles",
+  "pos_weight_source": "tiles",
+  "pos_weight_cap": 50.0,
+  "batch_size": 32,
+  "eval_batch_size": 1,
+  "epochs": 10,
+  "learning_rate": 0.0002,
+  "weight_decay": 0.0001,
+  "base_channels": 32,
+  "dropout": 0.1,
+  "norm_type": "group",
+  "norm_groups": 8,
+  "init_head_bias_from_positive_rate": true,
+  "augment_flip": true,
+  "threshold": 0.5,
+  "metric_thresholds": [
+    0.1,
+    0.2,
+    0.3,
+    0.5,
+    0.7,
+    0.9
+  ],
+  "topk_area_fractions": [
+    0.01,
+    0.05,
+    0.1
+  ],
+  "fss_radii": [
+    1,
+    2,
+    4,
+    8
+  ],
+  "reliability_bins": 10,
+  "amp": true,
+  "seed": 7,
+  "use_aux_spatial_head": true,
+  "aux_spatial_radius": 2,
+  "aux_spatial_loss_weight": 0.5,
+  "train_target_mode": "dilate_max",
+  "train_target_radius": 2,
+  "loss_type": "bce",
+  "init_checkpoint": ""
+}