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/lip_processor.py

@@ -235,7 +235,7 @@ def process_lip(
                     )
                 else:
                     landmarks = None
-        except Exception as e:
+        except Exception:
             landmarks = None
 
         if landmarks is not None and len(landmarks) >= 468: