fix(topology): TerminalPreviewPopover renderTrigger=false prop kills duplicate tab stop

Forward-fix #1 on 5f92ecc. Guard a11y finding: each TerminalView card
exposed TWO focusable controls — the full-card absolute-inset trigger
button AND the popover's internal trigger button (rendered with
buttonClassName="sr-only" so visually hidden but still keyboard-
reachable). Sighted keyboard users would hit two tab stops for the
same action; sensible-tab-order check failed.

Resolution per guard recommendation (a): teach TerminalPreviewPopover
an external-trigger mode.

- New optional prop `renderTrigger?: boolean` on
  TerminalPreviewPopover (default true preserves graph + table view
  callers). When false, the popover skips its internal button
  entirely; the wrapper div + event-listening logic + portal popover
  still mount so the card's own trigger can dispatch
  TERMINAL_PREVIEW_EVENT and have this instance render the positioned
  popover.
- SeatTerminalCard updated from buttonClassName="sr-only" →
  renderTrigger={false}. Same anchor positioning via wrapperClassName;
  zero focusable button claim.

Regression test added in p5-topology-terminal.test.tsx:
'each terminal card exposes exactly one tab-reachable trigger button
(no duplicate sr-only popover button)' — renders 2 seats, asserts:
- 2 card-level triggers (button[data-testid^='terminal-card-trigger-'])
- 0 popover-trigger buttons (button[data-testid$='-terminal-open'])

Discrimination verified: temporarily reverted ONLY
TopologyTerminalView.tsx back to buttonClassName="sr-only" (kept
TerminalPreviewPopover + new test) → the assertion fails (2 popover
trigger buttons render). Restored renderTrigger={false} → 11/11
PASS.

Tests:
- p5-topology-terminal.test.tsx: 11/11 PASS (1 new).
- Full daemon suite: 3379 passed / 1 skipped / 0 failed.
- git diff --check clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

packages/ui/src/components/topology/TerminalPreviewPopover.tsx

@@ -41,6 +41,13 @@ interface TerminalPreviewPopoverProps {
   buttonClassName?: string;
   popoverClassName?: string;
   testIdPrefix: string;
+  /** V0.3.1 slice 14 forward-fix #1 (a11y): when false, the popover
+   *  does NOT render its own trigger button. Used by surfaces that
+   *  own the trigger externally (e.g., TerminalView cards where the
+   *  whole card acts as the trigger) so the popover doesn't add a
+   *  duplicate keyboard tab stop. Default true preserves the
+   *  existing graph-view + table-view button rendering. */
+  renderTrigger?: boolean;
 }
 
 function rectFromElement(el: HTMLElement | null): AnchorRect {
@@ -90,6 +97,7 @@ export function TerminalPreviewPopover({
   buttonClassName,
   popoverClassName,
   testIdPrefix,
+  renderTrigger = true,
 }: TerminalPreviewPopoverProps) {
   const key = `${rigId ?? "unknown"}:${logicalId}`;
   const rootRef = useRef<HTMLDivElement | null>(null);
@@ -188,16 +196,18 @@ export function TerminalPreviewPopover({
 
   return (
     <div ref={rootRef} className={cn("relative inline-flex", wrapperClassName)}>
-      <button
-        type="button"
-        data-testid={`${testIdPrefix}-terminal-open`}
-        aria-label={`View ${logicalId} terminal`}
-        title="View terminal"
-        onClick={openPreview}
-        className={buttonClassName}
-      >
-        <ToolMark tool="terminal" size="sm" />
-      </button>
+      {renderTrigger ? (
+        <button
+          type="button"
+          data-testid={`${testIdPrefix}-terminal-open`}
+          aria-label={`View ${logicalId} terminal`}
+          title="View terminal"
+          onClick={openPreview}
+          className={buttonClassName}
+        >
+          <ToolMark tool="terminal" size="sm" />
+        </button>
+      ) : null}
       {popover}
     </div>
   );

packages/ui/src/components/topology/TopologyTerminalView.tsx

@@ -134,7 +134,7 @@ function SeatTerminalCard({ seat }: { seat: NodeInventoryEntry }) {
           reducedMotion={false}
           testIdPrefix={`terminal-grid-${seat.rigId}-${seat.logicalId}`}
           wrapperClassName="absolute right-1 top-1 z-20"
-          buttonClassName="sr-only"
+          renderTrigger={false}
         />
       ) : null}
       <header className="relative z-0 flex items-center justify-between gap-2 pointer-events-none">

packages/ui/test/p5-topology-terminal.test.tsx

@@ -223,6 +223,41 @@ describe("TopologyTerminalView P5-7 grid", () => {
   });
 });
 
+// V0.3.1 slice 14 walk-item 17 forward-fix #1 (a11y): each terminal
+// card exposes EXACTLY ONE tabbable trigger control. The TerminalPreview-
+// Popover instance is mounted with `renderTrigger={false}` so the card's
+// full-card overlay button is the sole interaction surface; a duplicate
+// invisible-but-reachable sr-only popover button would fail
+// sensible-tab-order a11y review.
+describe("TerminalView card a11y (slice 14 FF#1)", () => {
+  it("each terminal card exposes exactly one tab-reachable trigger button (no duplicate sr-only popover button)", async () => {
+    const seats = [
+      makeSeat({ logicalId: "alpha" }),
+      makeSeat({ logicalId: "beta" }),
+    ];
+    setupFetch({ rigs: [{ id: "rig-1", name: "test-rig" }], seatsByRig: { "rig-1": seats } });
+    const { findByTestId, container } = withQueryClient(
+      <TopologyTerminalView scope="rig" rigId="rig-1" />,
+    );
+    await findByTestId("topology-terminal-grid");
+
+    // Exactly one card-level trigger button per seat.
+    const cardTriggers = container.querySelectorAll(
+      "button[data-testid^='terminal-card-trigger-']",
+    );
+    expect(cardTriggers).toHaveLength(2);
+
+    // ZERO duplicate sr-only popover buttons — the FF removes them.
+    // Pre-fix: each card mounted a `terminal-grid-<rig>-<seat>-terminal-open`
+    // button via the popover's default trigger render. With
+    // renderTrigger={false} the popover skips its button entirely.
+    const popoverTriggerButtons = container.querySelectorAll(
+      "button[data-testid$='-terminal-open']",
+    );
+    expect(popoverTriggerButtons).toHaveLength(0);
+  });
+});
+
 describe("globals.css pulsing-ring CSS contract (ritual #7 pseudo-element-paint)", () => {
   const cssPath = path.resolve(__dirname, "../src/globals.css");
   it("globals.css declares @keyframes terminal-card-active-frames", () => {