fix(ui): restore startup budget margin (#125891)

Move GitHub markdown label formatting back behind the markdown loading boundary and exercise markdown-table interactions through the real delegated click owner. This restores startup bundle margin without changing the committed budget baseline and prevents the isolated table test from depending on leaked listeners.

ui/src/components/github-link-target.ts

@@ -13,7 +13,7 @@ export type GitHubLinkTarget = GitHubItemTarget & {
   href: string;
 };
 
-function decodePathSegment(value: string): string | null {
+export function decodeGitHubPathSegment(value: string): string | null {
   try {
     const decoded = decodeURIComponent(value).trim();
     return decoded && decoded !== "." && decoded !== ".." ? decoded : null;
@@ -22,10 +22,10 @@ function decodePathSegment(value: string): string | null {
   }
 }
 
-function parseGitHubItemPath(url: URL): GitHubItemTarget | null {
+export function parseGitHubItemPath(url: URL): GitHubItemTarget | null {
   const segments = url.pathname.split("/").filter(Boolean);
-  const owner = decodePathSegment(segments[0] ?? "");
-  const repo = decodePathSegment(segments[1] ?? "");
+  const owner = decodeGitHubPathSegment(segments[0] ?? "");
+  const repo = decodeGitHubPathSegment(segments[1] ?? "");
   const surface = segments[2];
   const numberText = segments[3] ?? "";
   if (!owner || !repo || !/^[1-9]\d{0,9}$/.test(numberText)) {
@@ -52,35 +52,12 @@ export function parseGitHubLinkTarget(href: string): GitHubLinkTarget | null {
   return target ? { ...target, href: url.href } : null;
 }
 
-export function formatGitHubLinkLabel(url: URL): string {
-  const segments = url.pathname.split("/").filter(Boolean);
-  const item = parseGitHubItemPath(url);
-  if (item && segments.length === 4 && !url.search && !url.hash) {
-    return `#${item.number}`;
-  }
-  if (item) {
-    return url.href;
-  }
-  if (segments.length === 2) {
-    return segments.map((segment) => decodePathSegment(segment) ?? segment).join("/");
-  }
-  if (segments[2] === "blob" && segments.length > 4) {
-    const filename = decodePathSegment(segments.at(-1) ?? "");
-    if (filename) {
-      return filename;
-    }
-  }
-  const fallbackSegments = segments.length > 2 ? segments.slice(2) : segments;
-  const path = fallbackSegments.map((segment) => decodePathSegment(segment) ?? segment);
-  return ["github.com", ...path].join("/");
-}
-
 export function gitHubProfileUrl(login: string): string {
   return `https://${GITHUB_HOST}/${encodeURIComponent(login)}`;
 }
 
-// Built from the parsed parts rather than the source href, which isGitHubItemRootPath
-// shows may already carry its own sub-path, query, or comment fragment.
+// Build from parsed parts because the source href may already carry its own
+// sub-path, query, or comment fragment.
 export function gitHubFilesChangedUrl(target: GitHubItemTarget): string {
   const repoPath = `${encodeURIComponent(target.owner)}/${encodeURIComponent(target.repo)}`;
   return `https://${GITHUB_HOST}/${repoPath}/pull/${target.number}/files`;

ui/src/components/markdown-parser.ts

@@ -3,7 +3,7 @@ import markdownItTaskLists from "markdown-it-task-lists";
 import type Token from "markdown-it/lib/token.mjs";
 import { t } from "../i18n/index.ts";
 import { fileKindForPath, shortestFileLabels } from "./file-kind.ts";
-import { formatGitHubLinkLabel } from "./github-link-target.ts";
+import { decodeGitHubPathSegment, parseGitHubItemPath } from "./github-link-target.ts";
 import {
   installAssistantTranscriptRoleImageRenderer,
   installAssistantTranscriptRoleMarkdown,
@@ -108,6 +108,26 @@ function parseWebLinkHref(href: string): URL | null {
   return url.protocol === "https:" || url.protocol === "http:" ? url : null;
 }
 
+function formatGitHubLinkLabel(url: URL): string {
+  const segments = url.pathname.split("/").filter(Boolean);
+  const item = parseGitHubItemPath(url);
+  if (item) {
+    return segments.length === 4 && !url.search && !url.hash ? `#${item.number}` : url.href;
+  }
+  if (segments.length === 2) {
+    return segments.map((segment) => decodeGitHubPathSegment(segment) ?? segment).join("/");
+  }
+  if (segments[2] === "blob" && segments.length > 4) {
+    const filename = decodeGitHubPathSegment(segments.at(-1) ?? "");
+    if (filename) {
+      return filename;
+    }
+  }
+  const fallbackSegments = segments.length > 2 ? segments.slice(2) : segments;
+  const path = fallbackSegments.map((segment) => decodeGitHubPathSegment(segment) ?? segment);
+  return ["github.com", ...path].join("/");
+}
+
 function isFileLinkBoundaryBefore(value: string, index: number): boolean {
   const char = value[index - 1];
   return char === undefined || /\s/.test(char) || "([{<\"'`".includes(char);

ui/src/components/markdown-tables.test.ts

@@ -77,16 +77,11 @@ function interactiveOwner(): {
     scrollLeft: { configurable: true, value: 0, writable: true },
     scrollWidth: { configurable: true, value: 300 },
   });
+  owner.addEventListener("click", handleMarkdownTableInteraction);
   enhanceMarkdownTables(owner);
   return { owner, shell, viewport };
 }
 
-function markdownTableInteractionEvent(target: Element): Event {
-  const event = new MouseEvent("click", { bubbles: true });
-  Object.defineProperty(event, "target", { value: target });
-  return event;
-}
-
 describe("Markdown table interactions", () => {
   beforeEach(() => {
     TestMutationObserver.instances = [];
@@ -174,8 +169,7 @@ describe("Markdown table interactions", () => {
     vi.useFakeTimers();
     const { owner } = interactiveOwner();
     const copy = owner.querySelector<HTMLButtonElement>(".markdown-table__copy")!;
-
-    handleMarkdownTableInteraction(markdownTableInteractionEvent(copy));
+    copy.click();
 
     expect(writeText).toHaveBeenCalledWith("Name\tValue\nAlpha\tOne");
     await vi.advanceTimersByTimeAsync(0);
@@ -190,8 +184,7 @@ describe("Markdown table interactions", () => {
     const { owner } = interactiveOwner();
     const expand = owner.querySelector<HTMLButtonElement>(".markdown-table__expand")!;
     expand.focus();
-
-    handleMarkdownTableInteraction(markdownTableInteractionEvent(expand));
+    expand.click();
 
     const dialog = document.querySelector<HTMLDialogElement>(".markdown-table-dialog")!;
     expect(dialog.hasAttribute("open")).toBe(true);
@@ -212,10 +205,7 @@ describe("Markdown table interactions", () => {
     expect(document.querySelector(".markdown-table-dialog")).toBeNull();
     expect(document.activeElement).toBe(expand);
 
-    // Reopen through the handler like every other interaction here: the file
-    // runs in the isolated lane, so no shared-graph document listener exists
-    // to service a raw click().
-    handleMarkdownTableInteraction(markdownTableInteractionEvent(expand));
+    expand.click();
     const reopenedDialog = document.querySelector<HTMLDialogElement>(".markdown-table-dialog")!;
 
     reopenedDialog.querySelector<HTMLButtonElement>(".markdown-table-dialog__close")!.click();