docs: restore the classification matrix and re-cut the graph for mobile (#862)

Three fixes to the README architecture graph.

**The classification matrix is back.** It was dropped when the graph was
sized down for the README column, on the grounds that its 10px axis
labels fall under the type floor. That was the wrong call — without it
the two conductors read as an arbitrary hand-off, and the matrix
registers as a *shape* (a scan sweep, one rust cell) long before anyone
reads the words. It now sits centred over the level-2 conductor: the
sweep lands on UNCERTAIN, the escalation fires, level 3 resolves it to
CRITICAL.

**The REJECTED label was orphaned.** It sat at x=392 while the rejection
loop runs between x=586 and x=958 — floating text with nothing attached
to it. Moved under the loop's low point, and the loop was raised
slightly to open the gap.

**The animation was slow on phones.** Not a rendering bug — an encoding
one. Animated WebP is CPU-decoded with no frame-dropping, so when a
phone falls behind it stretches the animation instead of skipping ahead.
The old encode made that worse two ways: it carried an alpha channel on
396 of 536 frames despite every source frame being opaque RGB, and wrote
a full keyframe every ~5 frames.

| | before | after |
|---|---|---|
| size (pair) | 6.6 MB | **1.3 MB** |
| decoded per loop | 252 MP | **76 MP** |
| alpha frames | 396 | **0** |
| fps | 25 | 15 |

Width stays 1856px, so the retina supply ratio for an ~890px column is
unchanged.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Eivind <eivindcovibes.ai@Eivinds-MacBook-Pro.local>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

Author: 3 people

README.md

@@ -29,10 +29,10 @@ Zeroshot is an open-source, multi-agent orchestration engine for autonomous soft
 <div align="center">
   <picture>
     <source media="(prefers-color-scheme: dark)" srcset="docs/assets/zeroshot-architecture-dark.webp">
-    <img alt="One Zeroshot run drawn as a graph: an issue enters, a junior conductor escalates to a senior one, the config router sizes the cluster, a planner and worker execute, two stages of validators judge the result, the run is rejected once and approved on the second pass, and every event is appended to the ledger" src="docs/assets/zeroshot-architecture-light.webp" width="100%">
+    <img alt="One Zeroshot run drawn as a graph: an issue enters, a level-2 conductor scores it on a complexity matrix, lands on uncertain and escalates to level 3, which calls it critical; the config router sizes the cluster, a planner and worker execute, two stages of validators judge the result, and the change is rejected once before it is approved" src="docs/assets/zeroshot-architecture-light.webp" width="100%">
   </picture>
   <br>
-  <em>One run, drawn as it happens. The conductor escalates to a senior model, the router sizes the cluster, and the change is rejected once before it is approved.</em>
+  <em>One run, drawn as it happens. A conductor scores the issue, escalates what it can't call, the router sizes the cluster, and the change is rejected once before it is approved.</em>
 </div>
 
 ## Install