fix(gate): close the gaps in the plan-code guard, the button lists and the tooling

- planCodes: the quote and slash lookarounds let the commonest form through (a docstring or test
  title opening with a code, a slash pair); the two real exceptions (an episode titled "E1", ruff's
  E4/E7/E9) are now named and cut first, with cases that fail on the old pattern. audit_metrics
  counts by the same definition.
- button-primitive: both file lists live in the rule body, out of sight of the snapshot and the
  register; each is now pinned to its exact set of ui/ files (red when either is widened).
- check.sh --brief shows a short log whole and keeps the line before each hit, so ruff's rule and
  eslint's file path survive the excerpt.
- lint-changed runs prettier over every changed frontend file, as the gate does, not only code.
- CLAUDE.md and gates.md no longer claim the basedpyright baseline was found harmless: it was never
  triaged, and the reportOptional* entries are the likeliest real bugs.

frontend/src/lib/buttonPrimitive.contract.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from "vitest";
 
-import { eslint } from "./lintProbe.testkit";
+import { eslint, uiFiles } from "./lintProbe.testkit";
 
 // `local/button-primitive` (eslint.config.js): one primitive per button family (docs/DESIGN.md).
 // 268 hand-rolled buttons were swept onto ui/Button, IconButton, Pressable, Chip and
@@ -43,6 +43,37 @@ describe("a hand-rolled button", () => {
     ).toBe(0);
   });
 
+  // The primitive list lives in the rule body, where neither the gate snapshot nor docs/gates.md
+  // sees it, so this holds it to exactly these files of ui/.
+  it("is allowed in exactly the control primitives of ui/", { timeout: 60_000 }, async () => {
+    const allowed: string[] = [];
+    for (const file of uiFiles())
+      if (
+        (await hits(
+          'export const R = () => <button type="button">x</button>;\n',
+          `src/components/ui/${file}`,
+        )) === 0
+      )
+        allowed.push(file);
+    expect(allowed).toEqual([
+      "AnchoredPopover.tsx",
+      "Button.tsx",
+      "Chip.tsx",
+      "Combobox.tsx",
+      "DragHandle.tsx",
+      "FilterSelect.tsx",
+      "FocusSafeButton.tsx",
+      "IconButton.tsx",
+      "Pressable.tsx",
+      "PriorityStepper.tsx",
+      "SegmentedToggle.tsx",
+      "SelectTrigger.tsx",
+      "SortControl.tsx",
+      "Tabs.tsx",
+      "form.tsx",
+    ]);
+  });
+
   it("is refused spelled as an element with the button role; a component's role is its own", async () => {
     expect(await hits('export const F = () => <div role="button" tabIndex={0}>x</div>;\n')).toBe(1);
     expect(await hits('export const G = () => <span role="button">x</span>;\n')).toBe(1);