inspect: include a trail link in the post-to-trail confirmation

When a run posts its verdict to the trail, print a browser link in addition to the existing confirmation, e.g.:

Posted the review verdict to trail #466 as a finding. View the trail: https://entire.io/gh/entireio/cli/trails/466/review-profiles

trailWebURL builds <api base>/<forge>/<owner>/<repo>/trails/<number>/<branch> from the resolved trail target, matching the server's web layout and honoring ENTIRE_API_BASE_URL; it returns empty (link omitted) when the target lacks a trail number/forge/owner/repo. Local output and the failure path ('Could not post the review to the trail: ...') already confirm the outcome. Adds trailWebURL tests.