App Consuming Excessive Storage Space

### Description

We are receiving reports from users stating that our app is consuming a lot of storage space, even though they don't have any downloaded episodes.

- [Beta feedback](https://play.google.com/console/u/0/developers/7957760354032996428/app/4975504729640578607/user-feedback/review-details?reviewId=522d31f9-5c0f-4815-8d83-55da494d716d&corpus=BETA_FEEDBACK)

### Step-by-step reproduction instructions

I can't reproduce this issue

### Screenshots or screen recording

_No response_

### Did you search for existing bug reports?

- [x] I have searched for existing bug reports.

### Device, Operating system, and Pocket Casts app version

_No response_

### Investigations
- ~Hypothesis 1 - ExoPlayer Cache~ ❌ : https://github.com/Automattic/pocket-casts-android/issues/3661#issuecomment-2684947488
- Hypothesis 2 - podcast_episodes table ⚠️ : https://github.com/Automattic/pocket-casts-android/issues/3661#issuecomment-2685748416
- Hypothesis 3 - Failed download episodes 💡 : https://github.com/Automattic/pocket-casts-android/issues/3661#issuecomment-2685829122
- Hypothesis 4 - Libraries cache 💡: https://github.com/Automattic/pocket-casts-android/issues/3661#issuecomment-2685903392

Review the four hypotheses and their linked issue comments, starting with the unresolved podcast_episodes and failed-download possibilities. Because the report has no reproducible steps or device details, first establish a way to observe storage usage, then document the confirmed cause and how to verify the fix.

Written by the indexing model from the issue text.