Miner Activity heatmap hardcodes "last 30 days" - bring it in line with the dashboard's 7D / 35D / All selector

[pandadev66]

The Developer Activity heatmap on the miner profile page currently only shows a single, fixed time window. The prominent number above the heatmap is always labeled "contribution(s) in the last 30 days" with no option to widen or narrow the view.

This creates two issues for users:

1. No way to switch ranges. Users who want to see a tighter recent view (e.g. the past week) or a fuller historical view (e.g. all-time activity) have no control to do so. Other parts of the app let users pick between short, medium, and full-history windows, so this page feels inconsistent.

2. The "last 30 days" label can be misleading. For miners who have less than 30 days of history, the prominent number still says "in the last 30 days" even though there isn't 30 days of activity to count - the caption directly underneath the heatmap reflects the real window (e.g. "in the last 17 day(s)"), so the two numbers visibly disagree.

A user-selectable time range with a small set of sensible presets (e.g. short / medium / all-time) would resolve both problems and bring this view in line with how range selection works elsewhere in the app.

Repro:

1. Open any miner profile → Activity tab.
2. Notice that there is no control to change the heatmap's time window.
3. Open a miner with fewer than 30 days of merged history and observe that the big number's "last 30 days" label does not match the smaller caption rendered directly below the heatmap.