Problem

If a persisted session file on disk is malformed (for example, truncated JSON), load_session() can raise a JSON parsing error while restoring sessions.

Why this matters

One bad session file should not impact the whole restore flow. Right now, a corrupted file can interfere with startup/session reload behavior instead of being isolated.

Expected behavior

• Corrupted session files should be skipped safely.
• Valid session files should still be restored.
• We should log a warning so operators can identify and clean up bad files.

Proposed fix

• Guard JSON reading in the session load path.
• On read/parse failure, return a safe fallback ([]) and log a warning.
• Validate payload shape (must be a list) before returning it.

Validation

Add tests for:

• malformed JSON fallback
• non-list JSON payload fallback
• reload path restoring valid files while skipping malformed ones