bug(opportunities): per-row usage-history sparkline not visible in recommendations table (regression after #239/PR #801)

[cristim]

Repro

1. Navigate to Opportunities.
2. Observe each recommendation row.

Expected

Each recommendation row shows a usage-history sparkline (a mini chart visualizing historical usage).

Actual

(Status: Fail -- re-verification needed to confirm current behavior.)

Context

Issue #239 and PR #801 added usage_history + per-row sparkline feature. QA marked this row as Fail after the PR merged. Re-test needed to confirm whether the sparkline is absent or broken.

Sheet reference

Bugs and improvement suggestions tab, row 521.