Correct route and dynamic param extraction for Expo Router

[alwx]

extractDynamicRouteParams() works but:

• Transaction names are noisy/uninformative (index, (tabs)).
• Dynamic param extraction almost never finds matching keys, so spans rarely carry route.params.* attributes.
• useFullPathsForNavigationRoutes builds a path from nested navigators, but it joins React Navigation names, not Expo Router pathnames.
  

Here is what we can do: When Expo Router is active, derive the route from Expo Router's own state rather than from getCurrentRoute().name:

• Use the Expo Router path (e.g. /profile/[id]) as the canonical span name and route.name attribute.
• Extract dynamic params from the matched route pattern + the actual params object, including catch-all [...slug].
• Keep query-string params off the span by default; gate them behind sendDefaultPii (matching the existing PII model in deeplink.ts and the current extractDynamicRouteParams contract).
• Set route.path (templated) and, under sendDefaultPii, route.url (concrete).

[linear-code]

RN-633