revert(inspect-ui): drop HtmlPanel + html tab

Removes the iframe-based HTML viewer and its before/after tab wiring
from RunDetail.

inspect-ui/src/panels/HtmlPanel.css

@@ -1,60 +0,0 @@
-.html-panel {
-  display: flex;
-  flex-direction: column;
-  gap: 8px;
-}
-
-.html-toolbar {
-  display: flex;
-  gap: 4px;
-}
-
-.html-tab {
-  font-family: var(--font-mono);
-  font-size: 12px;
-  padding: 2px 10px;
-  background: var(--surface-1);
-  border: 1px solid var(--border);
-  color: var(--text-secondary);
-  cursor: pointer;
-}
-
-.html-tab-active {
-  color: var(--text-primary);
-  border-color: var(--border-strong, var(--border));
-}
-
-.html-frame {
-  width: 100%;
-  height: 480px;
-  border: 1px solid var(--border);
-  background: white;
-}
-
-.html-source {
-  font-family: var(--font-mono);
-  font-size: 11px;
-  color: var(--text-primary);
-  background: var(--surface-1);
-  border: 1px solid var(--border);
-  padding: 8px;
-  margin: 0;
-  max-height: 480px;
-  overflow: auto;
-  white-space: pre-wrap;
-  word-break: break-all;
-}
-
-.html-empty {
-  font-family: var(--font-mono);
-  font-size: 12px;
-  color: var(--text-secondary);
-  padding: 16px;
-}
-
-.html-error {
-  font-family: var(--font-mono);
-  font-size: 12px;
-  color: var(--text-violation, #c33);
-  padding: 16px;
-}

inspect-ui/src/panels/HtmlPanel.tsx

@@ -1,73 +0,0 @@
-import { useEffect, useState } from "react";
-import { htmlUrl } from "../api";
-import "./HtmlPanel.css";
-
-interface HtmlPanelProps {
-  runId: string;
-  fileName: string;
-  available: boolean;
-}
-
-type ViewMode = "render" | "source";
-
-export default function HtmlPanel({ runId, fileName, available }: HtmlPanelProps): JSX.Element {
-  const [mode, setMode] = useState<ViewMode>("render");
-  const [source, setSource] = useState<string | null>(null);
-  const [error, setError] = useState<string | null>(null);
-  const url = htmlUrl(runId, fileName);
-
-  useEffect(() => {
-    if (!available || mode !== "source") return;
-    let cancelled = false;
-    setSource(null);
-    setError(null);
-    fetch(url)
-      .then((response) => {
-        if (!response.ok) throw new Error(`${response.status} ${response.statusText}`);
-        return response.text();
-      })
-      .then((text) => {
-        if (!cancelled) setSource(text);
-      })
-      .catch((failure: unknown) => {
-        if (!cancelled) setError(failure instanceof Error ? failure.message : String(failure));
-      });
-    return () => {
-      cancelled = true;
-    };
-  }, [available, mode, url]);
-
-  if (!available) {
-    return <div className="html-empty">no html captured for this step</div>;
-  }
-
-  return (
-    <div className="html-panel">
-      <div className="html-toolbar">
-        <button
-          type="button"
-          className={mode === "render" ? "html-tab html-tab-active" : "html-tab"}
-          onClick={() => setMode("render")}
-        >
-          render
-        </button>
-        <button
-          type="button"
-          className={mode === "source" ? "html-tab html-tab-active" : "html-tab"}
-          onClick={() => setMode("source")}
-        >
-          source
-        </button>
-      </div>
-      {mode === "render" ? (
-        <iframe className="html-frame" src={url} sandbox="" title={fileName} />
-      ) : error ? (
-        <div className="html-error">failed to load: {error}</div>
-      ) : source === null ? (
-        <div className="html-empty">loading...</div>
-      ) : (
-        <pre className="html-source">{source}</pre>
-      )}
-    </div>
-  );
-}

inspect-ui/src/routes/RunDetail.tsx

@@ -4,7 +4,6 @@ import { getRun, getStep, screenshotUrl } from "../api";
 import type { Run, Step } from "../types";
 import ActionList from "../panels/ActionList";
 import HierarchyPanel from "../panels/HierarchyPanel";
-import HtmlPanel from "../panels/HtmlPanel";
 import Screenshot from "../panels/Screenshot";
 import SnapshotTable from "../panels/SnapshotTable";
 import ViolationsPanel from "../panels/ViolationsPanel";
@@ -142,21 +141,6 @@ export default function RunDetail() {
       label: "Hierarchy",
       content: <HierarchyPanel hierarchy={currentStep?.hierarchy} />,
     },
-    ...(runId && currentStep?.html_available
-      ? [
-          {
-            id: "html",
-            label: "HTML",
-            content: (
-              <HtmlPanel
-                runId={runId}
-                fileName={`step-${String(currentStep.step).padStart(5, "0")}.html`}
-                available
-              />
-            ),
-          } satisfies TabDefinition,
-        ]
-      : []),
     {
       id: "properties",
       label: "Properties",
@@ -213,21 +197,6 @@ export default function RunDetail() {
       label: "Hierarchy",
       content: <HierarchyPanel hierarchy={nextStep?.hierarchy ?? currentStep?.hierarchy} />,
     },
-    ...(runId && currentStep?.html_available
-      ? [
-          {
-            id: "html",
-            label: "HTML",
-            content: (
-              <HtmlPanel
-                runId={runId}
-                fileName={`step-${String(currentStep.step).padStart(5, "0")}-after.html`}
-                available
-              />
-            ),
-          } satisfies TabDefinition,
-        ]
-      : []),
     {
       id: "properties",
       label: "Properties",