fix(ci): give the nightly-windev issue body a reachable run link (TST-25 Check 6)

Exercising TST-25 acceptance Check 6 end-to-end showed the on-failure issue
step works — it has filed an issue on every red nightly since 2026-07-17
(#126-#139) — but that every one of those issues links `http://gitea:3000`,
the runner-internal origin Gitea hands the runner. That URL is correct for
the issue-creation API call (the job container resolves `gitea` only on the
docker network and has no LAN egress to the public origin) and unreachable
for anyone clicking out of the issue.

Keep `github.server_url` for the API call; add a `PUBLIC_SERVER_URL` job env
used only for the browser-facing link in the body. Verified with a
forced-failure probe run (677) whose issue (#140) carries a public link that
returns 200.

Also records Check 6 as done in scripts/ci/README.md and corrects the
2026-07-13 tracking entry that wrote the check off as abandoned.

.gitea/workflows/ci.yml

@@ -165,6 +165,14 @@ jobs:
     # visible even though nobody watches the Actions page.
     if: github.event_name == 'schedule'
     runs-on: ubuntu-latest
+    env:
+      # `github.server_url` is the URL Gitea hands the runner — the docker-network-internal
+      # `http://gitea:3000`. That is the right base for the issue-creation API call below (the job
+      # container resolves `gitea` only on that network, and has no LAN egress to the public origin),
+      # but it is useless as a link a human clicks out of the issue. So browser-facing URLs in the
+      # issue body use the public origin instead. TST-25 acceptance Check 6 caught this: every
+      # nightly issue since #126 carried an unreachable `http://gitea:3000/...` run link.
+      PUBLIC_SERVER_URL: https://gitea.dohertylan.com
     steps:
       - uses: actions/checkout@v4
       - name: Full Worker.Tests + live-MXAccess smoke on windev
@@ -184,7 +192,7 @@ jobs:
             -H "Authorization: token ${{ github.token }}" \
             -H "Content-Type: application/json" \
             "${{ github.server_url }}/api/v1/repos/${{ github.repository }}/issues" \
-            -d "{\"title\":\"nightly-windev failed on ${{ github.sha }}\",\"body\":\"The scheduled windev Worker + live-MXAccess run failed: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }} . A red nightly may mean the Windows tier is down rather than the change — see docs/GatewayTesting.md (Continuous Integration).\"}"
+            -d "{\"title\":\"nightly-windev failed on ${{ github.sha }}\",\"body\":\"The scheduled windev Worker + live-MXAccess run failed: ${PUBLIC_SERVER_URL}/${{ github.repository }}/actions/runs/${{ github.run_id }} . A red nightly may mean the Windows tier is down rather than the change — see docs/GatewayTesting.md (Continuous Integration).\"}"
 
   # NOTE: there is intentionally no native `windows` runner job. act_runner v0.6.1 host-mode on
   # Windows is broken and Windows containers are impractical for the net48/x86/MXAccess Worker, so the