Bug Hunt Investigation Prompt

There's a bug in [PROJECT/COMPONENT]. The symptom is: [DESCRIBE SYMPTOM].

Do not fix it yet. First, INVESTIGATE:
1. Read the relevant files. List file paths and line numbers you suspect.
2. Form 3 hypotheses about the root cause, ranked by likelihood.
3. For each hypothesis, describe how you'd verify it (a test, a log, a manual check).
4. Recommend the cheapest verification path to start with.

Report back with the investigation summary. I'll tell you which hypothesis to verify first. Then we fix.