shouldSaveDiscardedRecording permits Infinity duration and non-object settings

[hsusul]

Describe the bug

In src/helpers/discardedRecording.js:

1. shouldSaveDiscardedRecording(settings, durationSeconds, policyState = null) evaluates durationSeconds >= MIN_DISCARDED_DURATION_SECONDS. When durationSeconds is Infinity or non-finite, it returns true instead of false.
2. When settings is a non-object primitive (e.g. true or "invalid"), settings.dataRetentionEnabled and settings.saveDiscardedTranscriptions evaluate improperly or can cause unexpected policy rule evaluations.

To Reproduce

1. Call shouldSaveDiscardedRecording(settings, Infinity) -> returns true (expected false).
2. Call shouldSaveDiscardedRecording("invalid", 3) -> returns false but doesn't validate object type upfront.

Expected Behavior

• shouldSaveDiscardedRecording should return false if !settings || typeof settings !== "object".
• shouldSaveDiscardedRecording should return false if !Number.isFinite(durationSeconds) or durationSeconds < MIN_DISCARDED_DURATION_SECONDS.

[Chadpiha]

Closing together with #1806 — full reasoning over there. Thanks for the report, @hsusul!