fix(diagnosis): ship the CNN weights the Space was missing

Every /api/v1/diagnosis/predict on the live Space answered 503 "Diagnosis
model is not available": model_wrapper.load() raised FileNotFoundError
because the TorchScript export and its metadata were never committed.

The cause was one unanchored .gitignore pattern. `trained_artifacts_fast/`
has no leading slash, so git matched it at every depth -- it was meant for
the scratch copy training drops at the repo root, but it also swallowed
ml/post_symptom_diagnosis/saved_models/trained_artifacts_fast/. Every other
module ships its saved_models/; this one shipped a lone README, and the gap
read as intentional -- the top-level README documented the 503 under Known
Issues as "the CNN artifacts are not in this repo".

Anchor the pattern to /trained_artifacts_fast/ and commit the two files
inference actually reads. The .pt goes through LFS, which the Space requires
for binaries. The .pth checkpoint stays ignored: it is the training-side
fallback, no inference path opens it, and it would add 14 MB to the image
for nothing.

Verified by loading the wrapper from the shipped pair alone -- 88 classes,
img_size 192 -- and running a forward pass to a normalised top-3.

.gitignore

@@ -59,7 +59,18 @@ backend/.env.*
 backend/artifacts/*/advisor/
 backend/artifacts/edge/fallback_events.jsonl
 backend/artifacts/**/sync_state.json
-trained_artifacts_fast/
+
+# The scratch copy of the diagnosis CNN that training drops at the repo root.
+# The leading slash is load-bearing: written bare, this pattern matched at every
+# depth and silently swallowed the *real* artifacts under
+# ml/post_symptom_diagnosis/saved_models/trained_artifacts_fast/ too. They never
+# reached the Space, so model_wrapper.load() raised FileNotFoundError and every
+# /api/v1/diagnosis/predict answered 503 "Diagnosis model is not available".
+/trained_artifacts_fast/
+
+# The .pth checkpoint is the training-side fallback; inference only ever reads
+# the TorchScript export and the metadata JSON, so keep 14 MB out of the image.
+ml/post_symptom_diagnosis/saved_models/trained_artifacts_fast/*.pth
 
 # Local user files
 *.crdownload

README.md

@@ -439,7 +439,7 @@ Full walkthrough: [README_HUGGINGFACE.md](README_HUGGINGFACE.md).
 
 ## Known Issues & Limitations
 
-- **Disease diagnosis needs external weights.** The CNN artifacts are not in this repo. Place them at `ml/post_symptom_diagnosis/saved_models/trained_artifacts_fast/` (see that folder's README). Until then, `/api/v1/diagnosis/predict` returns an error.
+- **Disease diagnosis weights are LFS-tracked, so a plain clone won't run it.** The CNN artifacts now ship with the repo at `ml/post_symptom_diagnosis/saved_models/trained_artifacts_fast/`, but a clone made without Git LFS leaves the 14 MB TorchScript export as a 133-byte pointer file, and `/api/v1/diagnosis/predict` answers `503 Diagnosis model is not available`. Run `git lfs pull` after cloning.
 
 - **Dependency versions are load-bearing.** `scikit-learn==1.8.0` and `numpy>=2.0,<3` are pinned exactly because the committed models embed the library versions that serialized them. Installing a different scikit-learn breaks unpickling with `No module named '_loss'`, and every advisor request fails. Don't relax these pins without retraining.
 

ml/post_symptom_diagnosis/saved_models/README.md

@@ -7,14 +7,25 @@ This directory stores the trained model artifacts for the **Post-Symptom Diagnos
 ```
 saved_models/
 └── trained_artifacts_fast/
-    ├── best_plant_disease_model_fast.pth          # PyTorch checkpoint (fallback)
-    ├── class_metadata_fast.json                   # Class names, crop mapping, img_size
-    └── plant_disease_model_fast_torchscript.pt    # TorchScript export (primary inference)
+    ├── class_metadata_fast.json                   # Class names, crop mapping, img_size — committed
+    └── plant_disease_model_fast_torchscript.pt    # TorchScript export, primary inference — committed via LFS
 ```
 
+Both files are committed, so the deployed Space can serve diagnoses. Only these
+two are: `best_plant_disease_model_fast.pth` is the training-side checkpoint and
+no inference path reads it, so `.gitignore` keeps its 14 MB out of the image.
+
 ## How to populate
 
-Copy the contents of the externally-trained `trained_artifacts_fast/` folder into `saved_models/trained_artifacts_fast/`.
+Nothing to do for a normal clone — but clone *with* Git LFS, or run `git lfs
+pull` afterwards. Without it the `.pt` stays a 133-byte pointer, `torch.jit.load`
+fails, and `/api/v1/diagnosis/predict` answers `503 Diagnosis model is not
+available`.
+
+After retraining, copy the fresh `trained_artifacts_fast/` contents over these
+files. Keep the `.gitignore` rule anchored as `/trained_artifacts_fast/` — written
+bare it matches at every depth and silently re-excludes this directory, which is
+exactly how the artifacts went missing from the Space before.
 
 ## Usage
 

ml/post_symptom_diagnosis/saved_models/trained_artifacts_fast/class_metadata_fast.json

@@ -0,0 +1,184 @@
+{
+  "class_names": [
+    "Apple__black_rot",
+    "Apple__healthy",
+    "Apple__rust",
+    "Apple__scab",
+    "Cassava__bacterial_blight",
+    "Cassava__brown_streak_disease",
+    "Cassava__green_mottle",
+    "Cassava__healthy",
+    "Cassava__mosaic_disease",
+    "Cherry__healthy",
+    "Cherry__powdery_mildew",
+    "Chili__healthy",
+    "Chili__leaf curl",
+    "Chili__leaf spot",
+    "Chili__whitefly",
+    "Chili__yellowish",
+    "Coffee__cercospora_leaf_spot",
+    "Coffee__healthy",
+    "Coffee__red_spider_mite",
+    "Coffee__rust",
+    "Corn__common_rust",
+    "Corn__gray_leaf_spot",
+    "Corn__healthy",
+    "Corn__northern_leaf_blight",
+    "Cucumber__diseased",
+    "Cucumber__healthy",
+    "Gauva__diseased",
+    "Gauva__healthy",
+    "Grape__black_measles",
+    "Grape__black_rot",
+    "Grape__healthy",
+    "Grape__leaf_blight_(isariopsis_leaf_spot)",
+    "Jamun__diseased",
+    "Jamun__healthy",
+    "Lemon__diseased",
+    "Lemon__healthy",
+    "Mango__diseased",
+    "Mango__healthy",
+    "Peach__bacterial_spot",
+    "Peach__healthy",
+    "Pepper_bell__bacterial_spot",
+    "Pepper_bell__healthy",
+    "Pomegranate__diseased",
+    "Pomegranate__healthy",
+    "Potato__early_blight",
+    "Potato__healthy",
+    "Potato__late_blight",
+    "Rice__brown_spot",
+    "Rice__healthy",
+    "Rice__hispa",
+    "Rice__leaf_blast",
+    "Rice__neck_blast",
+    "Soybean__bacterial_blight",
+    "Soybean__caterpillar",
+    "Soybean__diabrotica_speciosa",
+    "Soybean__downy_mildew",
+    "Soybean__healthy",
+    "Soybean__mosaic_virus",
+    "Soybean__powdery_mildew",
+    "Soybean__rust",
+    "Soybean__southern_blight",
+    "Strawberry___leaf_scorch",
+    "Strawberry__healthy",
+    "Sugarcane__bacterial_blight",
+    "Sugarcane__healthy",
+    "Sugarcane__red_rot",
+    "Sugarcane__red_stripe",
+    "Sugarcane__rust",
+    "Tea__algal_leaf",
+    "Tea__anthracnose",
+    "Tea__bird_eye_spot",
+    "Tea__brown_blight",
+    "Tea__healthy",
+    "Tea__red_leaf_spot",
+    "Tomato__bacterial_spot",
+    "Tomato__early_blight",
+    "Tomato__healthy",
+    "Tomato__late_blight",
+    "Tomato__leaf_mold",
+    "Tomato__mosaic_virus",
+    "Tomato__septoria_leaf_spot",
+    "Tomato__spider_mites_(two_spotted_spider_mite)",
+    "Tomato__target_spot",
+    "Tomato__yellow_leaf_curl_virus",
+    "Wheat__brown_rust",
+    "Wheat__healthy",
+    "Wheat__septoria",
+    "Wheat__yellow_rust"
+  ],
+  "class_to_crop": {
+    "Apple__black_rot": "Apple",
+    "Apple__healthy": "Apple",
+    "Apple__rust": "Apple",
+    "Apple__scab": "Apple",
+    "Cassava__bacterial_blight": "Cassava",
+    "Cassava__brown_streak_disease": "Cassava",
+    "Cassava__green_mottle": "Cassava",
+    "Cassava__healthy": "Cassava",
+    "Cassava__mosaic_disease": "Cassava",
+    "Cherry__healthy": "Cherry",
+    "Cherry__powdery_mildew": "Cherry",
+    "Chili__healthy": "Chili",
+    "Chili__leaf curl": "Chili",
+    "Chili__leaf spot": "Chili",
+    "Chili__whitefly": "Chili",
+    "Chili__yellowish": "Chili",
+    "Coffee__cercospora_leaf_spot": "Coffee",
+    "Coffee__healthy": "Coffee",
+    "Coffee__red_spider_mite": "Coffee",
+    "Coffee__rust": "Coffee",
+    "Corn__common_rust": "Corn",
+    "Corn__gray_leaf_spot": "Corn",
+    "Corn__healthy": "Corn",
+    "Corn__northern_leaf_blight": "Corn",
+    "Cucumber__diseased": "Cucumber",
+    "Cucumber__healthy": "Cucumber",
+    "Gauva__diseased": "Gauva",
+    "Gauva__healthy": "Gauva",
+    "Grape__black_measles": "Grape",
+    "Grape__black_rot": "Grape",
+    "Grape__healthy": "Grape",
+    "Grape__leaf_blight_(isariopsis_leaf_spot)": "Grape",
+    "Jamun__diseased": "Jamun",
+    "Jamun__healthy": "Jamun",
+    "Lemon__diseased": "Lemon",
+    "Lemon__healthy": "Lemon",
+    "Mango__diseased": "Mango",
+    "Mango__healthy": "Mango",
+    "Peach__bacterial_spot": "Peach",
+    "Peach__healthy": "Peach",
+    "Pepper_bell__bacterial_spot": "Pepper_bell",
+    "Pepper_bell__healthy": "Pepper_bell",
+    "Pomegranate__diseased": "Pomegranate",
+    "Pomegranate__healthy": "Pomegranate",
+    "Potato__early_blight": "Potato",
+    "Potato__healthy": "Potato",
+    "Potato__late_blight": "Potato",
+    "Rice__brown_spot": "Rice",
+    "Rice__healthy": "Rice",
+    "Rice__hispa": "Rice",
+    "Rice__leaf_blast": "Rice",
+    "Rice__neck_blast": "Rice",
+    "Soybean__bacterial_blight": "Soybean",
+    "Soybean__caterpillar": "Soybean",
+    "Soybean__diabrotica_speciosa": "Soybean",
+    "Soybean__downy_mildew": "Soybean",
+    "Soybean__healthy": "Soybean",
+    "Soybean__mosaic_virus": "Soybean",
+    "Soybean__powdery_mildew": "Soybean",
+    "Soybean__rust": "Soybean",
+    "Soybean__southern_blight": "Soybean",
+    "Strawberry___leaf_scorch": "Strawberry",
+    "Strawberry__healthy": "Strawberry",
+    "Sugarcane__bacterial_blight": "Sugarcane",
+    "Sugarcane__healthy": "Sugarcane",
+    "Sugarcane__red_rot": "Sugarcane",
+    "Sugarcane__red_stripe": "Sugarcane",
+    "Sugarcane__rust": "Sugarcane",
+    "Tea__algal_leaf": "Tea",
+    "Tea__anthracnose": "Tea",
+    "Tea__bird_eye_spot": "Tea",
+    "Tea__brown_blight": "Tea",
+    "Tea__healthy": "Tea",
+    "Tea__red_leaf_spot": "Tea",
+    "Tomato__bacterial_spot": "Tomato",
+    "Tomato__early_blight": "Tomato",
+    "Tomato__healthy": "Tomato",
+    "Tomato__late_blight": "Tomato",
+    "Tomato__leaf_mold": "Tomato",
+    "Tomato__mosaic_virus": "Tomato",
+    "Tomato__septoria_leaf_spot": "Tomato",
+    "Tomato__spider_mites_(two_spotted_spider_mite)": "Tomato",
+    "Tomato__target_spot": "Tomato",
+    "Tomato__yellow_leaf_curl_virus": "Tomato",
+    "Wheat__brown_rust": "Wheat",
+    "Wheat__healthy": "Wheat",
+    "Wheat__septoria": "Wheat",
+    "Wheat__yellow_rust": "Wheat"
+  },
+  "num_classes": 88,
+  "img_size": 192
+}

ml/post_symptom_diagnosis/saved_models/trained_artifacts_fast/plant_disease_model_fast_torchscript.pt

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:878a6a60624e180f0fa295fed20a2a8532faa6e7f6cc37719465f6850cd13f66
+size 14678584