The Flow panel lists the merge queue's last gates: the pulls in each, green or red, and the first failing test by name #7508

Intent: when landing stalls, the owner sees why in one look in the browser. Today GET …/queue/gates, MCP queue_gates and the terminal's Flow dialog read recentGates (src/checks/gate_result.ts); the web Flow panel shows only counts.

Done:

• [ ] src/web/pages/flow-panel.ts draws a "Last gates" card: the newest 10 gates, one row each with when, the pulls as links (#N #M), the verdict word, and on red the first failing test's name and its first error line, escaped. It uses one recentGates read per repository shown.
• [ ] Visibility is the panel's own; a sealed pull is shown as a sealed pull, never by title.
• [ ] Run bun scripts/design-lint.ts, with no new component class unless it is named in docs/design/areas/.
• [ ] A test (e.g. test/flow-panel-gates.test.ts) records a green and a red gate, renders the panel and finds both rows, the pull links and the failing test's name.

Files: src/web/pages/flow-panel.ts, a new test.

Risk: #7423 also edits the panel (hold pulls). Both add a section.