Fix review issues in cookie pattern handling

- Fix DurationInput fallback unit from "minutes" to "seconds" and add
  seconds as a selectable unit to prevent silent duration inflation
- Use parseFloat instead of parseInt for duration input to preserve
  fractional values
- Scope prefix merge groups by category ID to prevent cross-category
  merging
- Relink cookies and delete exact patterns even when prefix pattern
  already exists
- Prefer exact matches and longest prefix in pattern selection query
- Fix wrong error type in GetCookiePattern (ErrCookiePatternNotFound)
- Handle singular/plural in humanizeSeconds fallback branch

Signed-off-by: Émile Ré <emile@getprobo.com>

packages/helpers/src/duration.ts

@@ -29,5 +29,5 @@ export function humanizeSeconds(seconds: number | null): string {
       return `${count} ${count === 1 ? singular : plural}`;
     }
   }
-  return `${seconds} seconds`;
+  return `${seconds} ${seconds === 1 ? "second" : "seconds"}`;
 }