docs(planning): reconcile herd change-file body to measured ~70x/~3x

The design body still carried the pre-measurement ~10x/~1.2x placeholders and
a stale retry-ring mention. Align with the shipped model: httpware is bounded
near its max_attempts cap (~3x) at demo scale, naive ~70x; ring is CB+timeout.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: lesnik512

planning/changes/2026-07-19.02-resilience-demo-herd-and-enrich.md

@@ -48,24 +48,30 @@ plotting calls-into-the-backend per tick over a *sustained* outage window:
   clustering, not literal lockstep — arrivals are spread, fixed backoff *preserves*
   the clustering).
 - **httpware lane:** 20 clients, full-jitter backoff + per-client budget → jitter
-  decorrelates retry timing into a near-constant rate; each client's own budget caps
-  its own amplification.
+  decorrelates retry timing into a near-constant rate; at this client count each
+  client's `max_attempts=3` cap is what bounds its amplification (the per-client
+  budget's floor doesn't bind until far higher per-client volume — it's the guarantee
+  that holds as the herd grows).
 
 Both lanes reuse the *real* retry + budget models from the engine's source-of-truth
 constants block, one model instance per simulated client. **Fidelity framing that
 must hold:** the budget is **per-client**, not shared across the herd — at demo
-traffic levels the *visible* flattening is jitter decorrelating timing; the budget is
-the ceiling that keeps even a *longer* storm under ~1.2×. Copy says exactly that; it
-must not imply a shared/global budget.
+traffic levels the *visible* flattening is jitter decorrelating timing, and
+httpware's peak is bounded near its `max_attempts` cap (~3×), with the per-client
+budget the ceiling that holds as volume grows. Copy says exactly that; it must not
+imply a shared/global budget or that the budget (rather than `max_attempts`) does the
+capping at this scale.
 
 **Payoff metric.** The mini-tour spotlights the **peak load multiplier** — "backend
-saw N× baseline" (naive ~10×, httpware ~1.2×) — because it reads directly off the
-tallest spike the strip already draws (spotlight number == visible fact). **Total
-calls** during the outage is a secondary, un-spotlighted counter (volume story).
-"The flat rate leaves the backend room to recover" is the qualitative closing beat,
-*not* a spotlighted stat — httpware's code models no backend-recovery dynamic, so no
-invented recovery number. ~4 beats: outage hits → naive's first synchronized spike →
-httpware stays flat (jitter + budget) → peak-multiplier payoff.
+saw N× baseline". Measured against the fixed seed: **naive ~70×** (unbounded retries
+explode and keep climbing with outage length) **vs httpware ~3×** (bounded by
+`max_attempts` at this client count) — the number reads directly off the tallest
+spike the strip already draws (spotlight number == visible fact). **Total calls**
+during the outage is a secondary, un-spotlighted counter (volume story). "The flat
+rate leaves the backend room to recover" is the qualitative closing beat, *not* a
+spotlighted stat — httpware's code models no backend-recovery dynamic, so no invented
+recovery number. ~4 beats: outage hits → naive's first clustered spike → httpware
+stays flat (jitter + the `max_attempts` cap) → peak-multiplier payoff.
 
 **Enrich pass.**
 
@@ -103,11 +109,11 @@ size. Jagged failure shape is one `demos.css` change.
 `node --check docs/demos/engine.js`. Scratchpad jsdom harnesses extended: the
 existing `verify-demos.js` / `verify-real-page.js` drive every stop including the new
 herd mini-tour to completion without stalling; a herd trace asserts naive peak
-multiplier ≫ httpware peak (dramatic gap) and that both lanes use the shared retry +
-budget models. Manual: retry page reads micro → macro top-to-bottom under
-mkdocs-material light and dark; countdown ring animates and empties on retry / CB /
-timeout; failure shape distinguishable in grayscale; `prefers-reduced-motion`
-degrades to stepped updates.
+multiplier ≫ httpware peak (dramatic gap, ~70× vs ~3×), httpware bounded near the
+`max_attempts` cap, and a fine bucket count for a smooth strip. Manual: retry page
+reads micro → macro top-to-bottom under mkdocs-material light and dark; countdown
+ring animates and empties on CB / timeout; failure shape distinguishable in
+grayscale; `prefers-reduced-motion` degrades to stepped updates.
 
 ## Risk