Land the warming-files line from branch scout/6547-a-pure-read-names-the-files-that-gained, with its history tested and each line naming its repository #6583

Replaces #6547. Pull #6560 (closed) built the read, the hourly samples (src/crew/hot_history.ts), and the warming lines on the /boards flow panel and in the terminal. The reviews found the privacy gating right; these asks remain, all of them, in one round:

Done:

• [ ] Branch scout/6547-a-pure-read-names-the-files-that-gained (head 1ec4c880) is brought up to date with main and opened as a new pull.
• [ ] Each warming line on the flow panel names its repository, as each hot-file line above it does, under a small "Warming" heading.
• [ ] hotTrend leaves out files already at the hot-file limit and rises of a single pull (0 → 1).
• [ ] Tests with at/now passed in: two samples 1 minute apart keep one; a 2-hour-old sample is pruned; among samples at 40, 60 and 85 minutes old, the 60-minute one is the baseline.
• [ ] One test drives learnPullFiles twice an hour apart and reads the warming line; removing the sampling call makes it fail.

Files: src/flow/hot_trend.ts, src/crew/hot_history.ts, src/crew/hot_files.ts, src/web/pages/flow-panel.ts, their tests.

Before pushing: bun x tsc --noEmit, the tests you touch, bun scripts/design-lint.ts.