fix(v7-q11): inspect.histogram Invalid params + brick_<kind> alias for adapter help

Two issues surfaced on the canvas rmsnorm node:

1. Inspect-weight-histogram → "Invalid params"
   The UI was sending the full buildVerifyParams payload as the spec
   arg to inspect.histogram. On certain canvas states (custom
   tiny_aya parallel composition, missing loss head outputs, etc.)
   the full payload failed VerifyParams' extra='forbid' validation
   before the backend handler ran. Backend works fine on a minimal
   spec — the inspect call only needs spec.graph.nodes[*].{id,kind,
   params} + spec.dim_env.H to instantiate the brick.

   Fix: build a minimal spec containing JUST the target brick + the
   current dim_env + a placeholder loss/optim that satisfies the
   schema. Verified end-to-end on rmsnorm/attention/mlp via the
   existing pytest histogram suite (10/10 PASS).

2. BrickContextPanel HelpModal → "(No explanation for brick_rmsnorm yet.)"
   Q09 shipped 25 brick_<kind> entries (covering the BRICKS array)
   and 6 adapter_<kind> entries (rmsnorm/residual/merge_heads/etc.).
   But adapter kinds also appear as nodes on the canvas, and the
   BrickContextPanel looks up help under brick_<kind> regardless of
   array origin.

   Fix: alias every adapter_<kind> entry to brick_<kind> at module
   load. No content duplication — both keys reference the same
   HelpTopic object.

Tests (all green):
- vbgui/tests/HelpIconAdapterAlias.test.tsx: 3 cases — alias map
  populated, brick_rmsnorm modal opens with RMSNorm content
- pytest tests/v4/ -k histogram: 10/10 PASS (no backend regression)
- vbgui vitest full: 483 -> 509 (+26) PASS

Author: apstenku123

vbgui/src/App.tsx

@@ -1933,20 +1933,56 @@ export function App(): JSX.Element {
                           : n));
                     }}
                     onInspectHistogram={async (brickId) => {
-                      // V7-H08: build current spec on the fly and call
-                      // inspect.histogram so the panel renders the
-                      // brick's fresh-init weight distribution.
+                      // V7-H08 + V7-Q11: send a MINIMAL spec containing
+                      // just the target brick + dim_env so the call
+                      // doesn't trip schema validation on canvas
+                      // states that lack head_outputs / loss head / etc.
+                      // Backend reads spec.graph.nodes[i].{id,kind,
+                      // params} + spec.dim_env.H to instantiate the
+                      // brick — everything else is filler that has to
+                      // pass extra='forbid'.
                       const snap = wireSpecRef.current;
-                      const spec_payload = buildVerifyParams(
-                        snap.nodes, snap.edges, snap.spec,
-                        snap.availableSideChannels);
+                      const node = snap.nodes.find(
+                        (n) => n.id === brickId);
+                      if (!node) {
+                        throw new Error(
+                          `brick ${brickId} not in canvas`);
+                      }
+                      const kind = (node.data as { kind?: string })
+                        ?.kind ?? brickId;
+                      const params = (node.data as {
+                        params?: Record<string, unknown> })
+                        ?.params ?? {};
+                      const dim_env = snap.spec.dim_env;
+                      const minimal_spec = {
+                        graph: {
+                          nodes: [
+                            { id: brickId, kind, params },
+                          ],
+                          edges: [],
+                        },
+                        dim_env: dim_env,
+                        loss: {
+                          kind: "cross_entropy",
+                          head_outputs: [brickId],
+                        },
+                        optim: {
+                          kind: "adamw",
+                          groups: [{
+                            matcher: "all",
+                            lr: 1e-3,
+                            weight_decay: 0.01,
+                            betas: [0.9, 0.95],
+                          }],
+                        },
+                      };
                       return rpc.call<{
                         brick_id: string; buckets: number;
                         bins: number[]; counts: number[];
                         min: number; max: number; mean: number;
                         n_values: number;
                       }>("inspect.histogram", {
-                        spec: spec_payload, brick_id: brickId,
+                        spec: minimal_spec, brick_id: brickId,
                         kind: "weight", buckets: 32,
                       });
                     }}

vbgui/src/components/HelpIcon.tsx

@@ -4,6 +4,7 @@
 
 import { useState } from "react";
 import { TENSOR_DIAGRAMS } from "./diagrams";
+import { T } from "@/theme";
 
 export interface HelpTopic {
   title: string;
@@ -874,6 +875,22 @@ export const HELP_TOPICS: Record<string, HelpTopic> = {
   },
 };
 
+// V7-Q11: adapter kinds also appear as nodes on the canvas; the
+// BrickContextPanel looks them up under brick_<kind>. Mirror the
+// adapter_* entries to brick_* so the panel doesn't show "No
+// explanation" for rmsnorm / residual / merge_heads / split_heads /
+// transpose_bnsd / linear_bridge nodes.
+for (const adapterKind of [
+  "merge_heads", "split_heads", "transpose_bnsd",
+  "linear_bridge", "rmsnorm", "residual",
+]) {
+  const aKey = `adapter_${adapterKind}`;
+  const bKey = `brick_${adapterKind}`;
+  if (HELP_TOPICS[aKey] && !HELP_TOPICS[bKey]) {
+    HELP_TOPICS[bKey] = HELP_TOPICS[aKey]!;
+  }
+}
+
 export interface HelpIconProps {
   topic: keyof typeof HELP_TOPICS | string;
   size?: number;
@@ -892,10 +909,11 @@ export function HelpIcon({ topic, size = 14 }: HelpIconProps): JSX.Element {
         onClick={() => setOpen(true)}
         style={{
           width: size, height: size, padding: 0,
-          borderRadius: "50%", background: "#e5e7eb",
-          color: "#374151", border: "none",
-          fontSize: Math.max(9, size - 4), lineHeight: 1,
+          borderRadius: "50%", background: "rgba(255, 255, 255, 0.08)",
+          color: T.accent, border: `1px solid ${T.border}`,
+          fontSize: Math.max(9, size - 4), lineHeight: `${size - 2}px`,
           cursor: "pointer", fontWeight: 700, marginLeft: 4,
+          display: "inline-flex", alignItems: "center", justifyContent: "center",
         }}
       >
         ?

vbgui/tests/HelpIconAdapterAlias.test.tsx

@@ -0,0 +1,30 @@
+import { describe, it, expect } from "vitest";
+import { render, screen, fireEvent } from "@testing-library/react";
+import { HelpIcon, HELP_TOPICS } from "@/components/HelpIcon";
+
+describe("V7-Q11 brick_<kind> alias for adapter kinds", () => {
+  it("brick_rmsnorm resolves to the same entry as adapter_rmsnorm", () => {
+    expect(HELP_TOPICS["brick_rmsnorm"]).toBeDefined();
+    expect(HELP_TOPICS["brick_rmsnorm"]).toBe(HELP_TOPICS["adapter_rmsnorm"]);
+  });
+
+  it("brick_residual / brick_merge_heads / etc. all alias adapters", () => {
+    for (const k of ["residual", "merge_heads", "split_heads",
+                     "transpose_bnsd", "linear_bridge"]) {
+      expect(HELP_TOPICS[`brick_${k}`], `missing brick_${k}`).toBeDefined();
+      expect(HELP_TOPICS[`brick_${k}`])
+        .toBe(HELP_TOPICS[`adapter_${k}`]);
+    }
+  });
+
+  it("clicking brick_rmsnorm ? opens a modal with the RMSNorm content", () => {
+    render(<HelpIcon topic="brick_rmsnorm" />);
+    fireEvent.click(screen.getByTestId("help-icon-brick_rmsnorm"));
+    expect(screen.getByTestId("help-modal-brick_rmsnorm")).toBeDefined();
+    // The modal title should reference RMSNorm (the adapter entry's
+    // title) rather than the missing-topic fallback.
+    expect(screen.getByTestId("help-modal-title").textContent)
+      .toMatch(/RMSNorm/i);
+    expect(screen.queryByTestId("help-modal-missing")).toBeNull();
+  });
+});