Symbol completions in the context picker now show "SymbolName filename.txt L123" instead of just "SymbolName". This helps distinguish between symbols with the same name in different files. ## Motivation I noticed that the message prompt editor only showed symbol names without any context, making it hard to use in large projects with many symbols sharing the same name. The inline prompt editor already includes file context for symbol completions, so I brought that same UX improvement to the message prompt editor. I've decided to match the highlighting style with directory completion entries from the message editor. ## Changes - Extract file name from both InProject and OutsideProject symbol locations - Add `build_symbol_label` helper to format labels with file context - Update test expectation for new label format ## Screenshots Inline Prompt Editor <img width="843" height="334" alt="Screenshot 2025-10-17 at 17 47 52" src="https://github.com/user-attachments/assets/16752e1a-0b8c-4f58-a0b2-25ae5130f18c" /> Old Message Editor: <img width="466" height="363" alt="Screenshot 2025-10-17 at 17 31 44" src="https://github.com/user-attachments/assets/900659f3-0632-4dff-bc9a-ab2dad351964" /> New Message Editor: <img width="482" height="359" alt="Screenshot 2025-10-17 at 17 31 23" src="https://github.com/user-attachments/assets/bf382167-f88b-4f3d-ba3e-1e251a8df962" /> Release Notes: - Added file names and line numbers to symbol completions in the agent panel