cleanup: remove dead code and duplicate docs

- Remove session-ses_2f27.md (161KB raw session log)
- Remove 49 ROOT_* duplicate files across REFERENCE/
- Remove 14 duplicate files between REFERENCE/ root and history/
- Remove asr_legacy.rs (dead code, replaced by asr.rs)
- Remove src/core/worker/ (duplicate JobWorker)
- Remove src/core/layers/ (empty directory)
- Remove 4 .bak files in src/
- Remove 7 dead private methods in worker/processor.rs
- Remove backup directory from git tracking

scripts/scene_classifier.py

@@ -230,7 +230,7 @@ class SceneClassifier:
                     print("[SCENE] Places365 model loaded successfully (365 classes)")
                 else:
                     print(
-                        f"[SCENE] Places365 model not found, using ImageNet pretrained"
+                        "[SCENE] Places365 model not found, using ImageNet pretrained"
                     )
                     self.model = models.resnet18(pretrained=True)
                     self.model_type = "imagenet"