`/` puts the cursor in the page's filter box on every list page, and `esc` hands the keys back #10935

Intent: keyboard-first lists like k9s (folded #3697): / filters.

Done:

• [ ] on issues, pulls, repos, runs and people lists, / focuses the list's filter field without typing a slash into it
• [ ] esc in the field blurs it so j/k work again
• [ ] / does nothing inside an input, textarea or the palette
• [ ] the ? sheet from #10922 lists / for pages that have a filter
• [ ] test of the key handler; design-lint clean; no layout shift

Files: src/web/script_keys.ts, one client script, its test Risks: collides with #10922 on key handling, hence it waits for it; do not steal / from the palette if it already owns it (check first, say which). Suggested: scout.

Planner: replaced by #11092, fresh from today's main. #10922 is no longer open, so it waits on nothing.