Pace was the missing dial, and the reachability test finally exists

"there are still balls which are basically not reachable with auto run..
please recheck" — and, asked twice: "did you write tests for the last issues
we encountered?" The straight answer: no. The unreachable-balls issue only
ever had config assertions, which is why it came back twice.

Pace is the ladder's fourth dial. Width alone never fixed reachability
because the returns left at ~27 m/s, crossing to the baseline in ~0.6s — less
than auto-run needs from the far corner. matchOppPace 0.78 puts opponent one
at ~20 m/s (measured live: twelve returns, 20.0-20.7), a quarter more flight
time, and matchOppPacePer hands it back per rung.

The vignette deepens: dmg x 0.8, cap 0.85, and the clean centre shrinks with
damage instead of only the rim darkening.

And the reachability regression the issue always deserved: a headless 90s
autopilot soak asserting at least 10 returns sampled and at most 15% that
never came within volley reach. Sabotage-verified. Its honest limit is
recorded in PROJECT.md: the autopilot attends perfectly and taps
frame-precisely, so it out-covers a human — it is a floor against
catastrophic regressions, not a proxy for the thumb. Oliver's playtest stays
the real gate.

46 tests, 15 seeds clean.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/config.js

@@ -394,6 +394,9 @@ export const TUNE = {
   matchFlub: 0.08,     // the match's own whiff base — the duel's 0.2 gives away a fifth of all
                        // returns, which across a game is an opponent that beats itself
   matchFlubKeep: 0.82, // ...and it keeps only this much per rung — the ladder now that hp is flat
+  matchOppPace: 0.78,   // scale on the opponent's return SPEED for opponent one (~21 m/s instead
+                        // of ~27) — the flight time auto-run needs. THE reachability dial
+  matchOppPacePer: 0.05,// ...climbing back per rung, capped at full pace
   matchWideBase: 2.1, // m either side of centre the FIRST opponent's returns may land — the width an
                       // auto-run player can actually cover. Its scatter painted lines from game one
                       // ("still a LOT of unreachable balls"); now line-painting is the late ladder