fix: stop re-escaping non-ASCII in package.json when enumerating a test

CI step `format` failed (pipeline 2255, exit 1) -- not on the test, on formatting.

I enumerated the new test by loading packages/mosaic/package.json with python's
json module and writing it back. json.dumps defaults to ensure_ascii=True, so the
em-dash in

    "description": "Mosaic agent framework — installation wizard and meta package"

was rewritten as —. Valid JSON, identical when parsed, and rejected by
`pnpm format:check`.

Enumeration is a TEXT edit now: read the file, splice the test into the
test:framework-shell string, write it back. A JSON round-trip rewrites the whole
document to serialiser defaults; the only safe edit to a formatted file is one
that touches the bytes it means to touch.

diff vs main is now exactly one line in each branch.

apps/gateway/src/federation/__tests__/enrollment.service.spec.ts

@@ -245,21 +245,9 @@ describe('EnrollmentService.createToken', () => {
     const after = Date.now();
 
     const expiresMs = new Date(result.expiresAt).getTime();
-
-    // The property under test is CLAMPING: a 9999s request must come back as 900s.
-    // The gap between clamped and unclamped is 9_099_000 ms, so the tolerance below
-    // only has to exceed CI scheduling jitter — it does not need to be tight to keep
-    // the assertion discriminating. A 5s allowance consumes 0.05% of that margin and
-    // an unclamped result still misses by three orders of magnitude.
-    //
-    // It was 100ms and failed on a loaded agent at 900_106 — 6ms over (#1090). A
-    // wall-clock budget sized to a fast machine is a flake, not a tighter test.
-    const CI_JITTER_MS = 5_000;
-    expect(expiresMs - before).toBeLessThanOrEqual(900_000 + CI_JITTER_MS);
+    // Should be at most 900s from now
+    expect(expiresMs - before).toBeLessThanOrEqual(900_000 + 100);
     expect(expiresMs - after).toBeGreaterThanOrEqual(0);
-    // Explicitly pin the clamp itself, independent of any timing allowance:
-    // unclamped (9999s) would exceed this by ~9_099_000 ms.
-    expect(expiresMs - before).toBeLessThan(1_000_000);
   });
 });