fix(editor): cap issue mention chip at container width, no clickable gap

#4288 swapped the chip cap from a fixed `max-w-72` to `max-w-[min(18rem,100%)]`.
A percentage max-width on a flex item is dropped while its flex-container wrapper
(`<a class="inline-flex">`) computes its own max-content size, so the wrapper
ballooned to the untruncated title width while the chip truncated to the cap —
leaving an empty, clickable strip after the visible chip.

Fix it as standard atomic-inline behavior instead of a fixed magic cap:
- IssueChip caps at `max-w-full` with the title truncating to an ellipsis, so it
  wraps to the next line as a unit and only truncates once a whole line can't
  hold it.
- Drop `inline-flex` from the editor NodeView `<a>` (issue + project) and the
  markdown AppLink so the chip's only wrapper is a plain inline box with a
  definite (line-based) percentage basis — no second flex container to balloon.

ProjectChip uses a definite `max-w-72`, so it never hit the gap; left as-is.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/views/editor/extensions/mention-view.tsx

@@ -69,7 +69,7 @@ function ProjectMention({
   };
 
   return (
-    <a href={projectPath} onClick={handleClick} className="project-mention inline-flex">
+    <a href={projectPath} onClick={handleClick} className="project-mention">
       <ProjectChip
         projectId={projectId}
         fallbackLabel={fallbackLabel}
@@ -101,7 +101,7 @@ function IssueMention({
   };
 
   return (
-    <a href={issuePath} onClick={handleClick} className="issue-mention inline-flex">
+    <a href={issuePath} onClick={handleClick} className="issue-mention">
       <IssueChip
         issueId={issueId}
         fallbackLabel={fallbackLabel}

packages/views/issues/components/issue-chip.test.tsx

@@ -49,7 +49,7 @@ describe("IssueChip", () => {
     render(<IssueChip issueId="issue-1" />);
 
     const chip = screen.getByText("MUL-3405").closest(".issue-mention");
-    expect(chip).toHaveClass("min-w-0", "max-w-[min(18rem,100%)]");
+    expect(chip).toHaveClass("min-w-0", "max-w-full");
     expect(screen.getByText("A very long issue title that should stay inside a narrow chat bubble"))
       .toHaveClass("min-w-0", "truncate");
   });

packages/views/issues/components/issue-chip.tsx

@@ -7,7 +7,13 @@ import { StatusIcon } from "./status-icon";
 
 /**
  * Compact, presentation-only representation of an issue —
- * `<StatusIcon> <identifier> <title>`, bordered, capped at 18rem or parent width.
+ * `<StatusIcon> <identifier> <title>`, bordered, capped at the container width
+ * (`max-w-full`) with the title truncating to an ellipsis. As an atomic inline
+ * box it wraps to the next line as a unit when it doesn't fit at the current
+ * position; the ellipsis only kicks in once a whole line can't hold it. The cap
+ * lives here (single source of truth) — wrappers must NOT add their own flex
+ * container around it, or a percentage cap gets dropped during the wrapper's
+ * intrinsic sizing and the clickable box diverges from the truncated chip.
  *
  * This is the single source of truth for the "issue-mention card" look.
  * It is intentionally **not** a link or button: callers wrap it in whatever
@@ -28,7 +34,7 @@ export interface IssueChipProps {
 }
 
 const BASE_CLASS =
-  "issue-mention inline-flex min-w-0 max-w-[min(18rem,100%)] items-center gap-1.5 rounded-md border mx-0.5 px-2 py-0.5 text-xs";
+  "issue-mention inline-flex min-w-0 max-w-full items-center gap-1.5 rounded-md border mx-0.5 px-2 py-0.5 text-xs";
 
 export function IssueChip({ issueId, fallbackLabel, className }: IssueChipProps) {
   const wsId = useWorkspaceId();

packages/views/issues/components/issue-mention-card.tsx

@@ -18,7 +18,7 @@ interface IssueMentionCardProps {
 export function IssueMentionCard({ issueId, fallbackLabel }: IssueMentionCardProps) {
   const p = useWorkspacePaths();
   return (
-    <AppLink href={p.issueDetail(issueId)} className="issue-mention not-prose inline-flex max-w-full align-middle">
+    <AppLink href={p.issueDetail(issueId)} className="issue-mention not-prose align-middle">
       <IssueChip
         issueId={issueId}
         fallbackLabel={fallbackLabel}