Testing: EdgeLearner missing test for multi-batch pagination (>100 entries)

[mrveiss]

Problem

`EdgeLearner.consume_feedback_stream()` paginates Redis streams in batches of 100 entries. The exclusive cursor approach (PR #2179) correctly handles pagination boundaries, but there is no test that verifies this with >100 entries.

A test with a multi-batch scenario (e.g. 150 entries across 2 xrange calls) would verify no duplicates or missed entries at pagination boundaries.

Discovered During

Code review of PR #2179 (issue #2102)

Fix

Add a test in `edge_learner_test.py` that mocks `xrange` returning 100 entries on the first call and 50 on the second, then verifies exactly 150 calls to `on_retrieval`.

Impact

Low — the code is correct, but the test gap means regressions could slip through.