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/generate_synonyms_llamacpp.py

@@ -100,7 +100,7 @@ def check_server_health(api_url: str) -> bool:
     except requests.exceptions.ConnectionError:
         print(f"❌ Cannot connect to llama.cpp server at {api_url}")
     except requests.exceptions.Timeout:
-        print(f"❌ Connection to llama.cpp server timed out")
+        print("❌ Connection to llama.cpp server timed out")
     return False
 
 
@@ -282,7 +282,7 @@ def main():
     # Check server health
     if not check_server_health(args.url):
         print("\n💡 Start llama.cpp server with:")
-        print(f"  llama-server --model <gemma4.gguf> --port 8081")
+        print("  llama-server --model <gemma4.gguf> --port 8081")
         sys.exit(1)
 
     # Prepare seed words