[Docs] Update MegaMoE handling and rerun benchmarks (#27726)

.claude/skills/cookbook-add-model/references/authoring-reference.md

@@ -109,13 +109,12 @@ the `_playground.jsx` header):
 | Axis key | Widget | Use when |
 |---|---|---|
 | `attention` | TP / CP / DP-Attention sub-knobs (DP-Attention is a combined knob: its value is the DP degree AND toggles `--enable-dp-attention`) | Model exposes parallelism knobs in its cells (§2.2) and you want users to override them. |
-| `moe` | Backend select + EP knob | Model is MoE and supports multiple `--moe-*-backend` choices. |
+| `moe` | Backend select (incl. MegaMoE) + EP knob; picking the MegaMoE backend reveals a Quantization sub-select (W4A8/W4A4) | Model is MoE and supports multiple `--moe-*-backend` choices. For Blackwell MoE kernel-fusion, give the `megamoe` backend option a `requiresHw` (and optional `excludesStrategy`) gate, then add a sibling `megamoeQuant` block (`{stripEnv, options}`): W4A8 = `NUM_MAX` only, W4A4 adds the FP4-activations env vars; both strip the DeepEP dispatch env. |
 | `parsers` | Multi-toggle | Model has reasoning / tool-call parsers. |
 | `speculative` | Single-select chip group | Model has spec-decoding presets you want to expose. |
 | `pdDisagg` | Mode + transfer backend (+ optional per-backend env via `envWhen` hw-gate) + IB device + optional `router{port, command}` | Model supports prefill/decode disaggregation. When a PD role is active and `router` is set, the playground shows the router (SGLang Model Gateway) launch command as a separate companion block and retargets the cURL modal to `router.port` (clients hit the router, not the role servers). |
 | `hicache` | Enable + storage + write policy | Model is large enough that hierarchical KV cache matters. |
 | `hisparse` | Enable + host-ratio select; whole card gated on the live PD-Disagg mode being `decode` | DSA-style model (DeepSeek-V3.2 / V4, GLM-5) that supports decode-side hierarchical sparse attention. |
-| `megamoe` | Single-select with hw/strategy gating | Blackwell-only kernel fusion variant. |
 
 **Per-chip constraints**: any chip entry in any axis can be wrapped with
 `hide` / `disable` constraint objects:

.claude/skills/cookbook-add-model/references/engine-axis.md

@@ -1,11 +1,12 @@
 # Engine extension: add a new playground feature axis
 
 Loaded on demand by the `cookbook-add-model` skill. **Rare** — adding a model
-cookbook is data-only and never needs this. The current 8 built-in axes
+cookbook is data-only and never needs this. The current 7 built-in axes
 (`attention`, `moe`, `parsers`, `speculative`, `pdDisagg`, `hicache`,
-`hisparse`, `megamoe`) already cover the SGLang feature surface most cookbooks
-need. Only add a new axis if a real cookbook needs it and the feature does not
-fit any existing axis. Touches `_playground.jsx` only.
+`hisparse`) already cover the SGLang feature surface most cookbooks need.
+(MegaMoE is not its own axis — it lives inside `moe` as a backend option +
+a `megamoeQuant` sub-select.) Only add a new axis if a real cookbook needs it
+and the feature does not fit any existing axis. Touches `_playground.jsx` only.
 
 For the per-model config/cells/MDX reference see [authoring-reference.md](authoring-reference.md).
 
@@ -94,7 +95,7 @@ Template:
   // also receives the derived
   // value (as `derived`) and may use it as a no-op shortcut when the
   // user's pick matches base. Skip when your axis owns flags that never
-  // appear in base cells (PD-Disagg / HiCache / MegaMoE).
+  // appear in base cells (PD-Disagg / HiCache).
   // deriveFromBase: (cell, fc, h) => ({ ... }) | null,
 
   // Optional: hints for the renderer. Currently only pdDisagg uses this
@@ -103,7 +104,7 @@ Template:
 
   // Returns the axis card JSX. The outer div MUST have key={axisId} so
   // React can track it in the engine's map loop. Return null for
-  // axis-level gating (e.g. MegaMoE on Hopper). Lay out as a single
+  // axis-level gating (e.g. HiSparse when the live PD mode isn't `decode`). Lay out as a single
   // compact horizontal row: title on the left, fields after.
   render: ({ axisId, value, setValue, fc, base, s, h, renderChip, renderSelect, derived }) => {
     if (/* axis-level gating fails */) return null;
@@ -147,7 +148,7 @@ Template:
     the **default** compact control (a `<select>` dropdown). It filters
     hidden chips and disables greyed-out ones internally — no per-chip
     `evaluateChip` loop needed in the render body. Most axes use it
-    (attention, moe, pdDisagg, hisparse, hicache, megamoe). Pass
+    (attention, moe, pdDisagg, hisparse, hicache). Pass
     `{ hideValues: [<sentinel>] }` when your `deriveFromBase` resolved to
     a real value, so the inherit-sentinel ("Auto" / "Inherited" /
     "current") doesn't clutter the dropdown.
@@ -206,7 +207,8 @@ emits flags that should land somewhere specific, include the most likely
 anchor prefixes in your call. Order doesn't matter (set semantics).
 
 **Conditional strips** — Some axes strip ONLY when overridden
-(`attention.tp`, `moe.backend`, `speculative`, `megamoe`). Others strip
+(`attention.tp`, `moe.backend` (incl. the MegaMoE quant env), `speculative`).
+Others strip
 UNCONDITIONALLY whenever declared (`parsers`, `pdDisagg`, `hicache`). The
 header comment in `AXIS_HANDLERS` documents which policy each axis uses;
 follow the same pattern when adding a new axis. If unsure, prefer
@@ -214,9 +216,9 @@ conditional strip — it preserves base behavior when the user does not
 opt in.
 
 **Closure of `AXIS_HANDLERS`** — Inside a handler method, you can
-reference `AXIS_HANDLERS.<otherAxis>` for cross-handler calls (megamoe
-does this for `_gateOpen`). This works because `AXIS_HANDLERS` is in
-lexical scope. Do NOT use this for general logic — it tightly couples
+reference `AXIS_HANDLERS.<otherAxis>` for cross-handler calls (no built-in
+axis currently needs this, but it works because `AXIS_HANDLERS` is in
+lexical scope). Do NOT use this for general logic — it tightly couples
 handlers. Reserve it for one handler's helpers shared between its own
 `render` and `revertHidden`.