refactor: one proof line per claim

Records that back the same field or issue claim share one line. Each
line says what the runs showed: the BIOS the core ran, the file strace
saw opened, or what a maintainer watched in an issue's run
(tests/campaign/observations.yml). A run with nothing to state stays
off the page.

.github/workflows/deploy-site.yml

@@ -73,8 +73,8 @@ on:
       - "release.json"
       - "derivable.json"
       - "measurements/**"
-      # The coverage table and the region results read the test game list.
-      - "tests/campaign/content.yml"
+      # The Proof lines of the emulator pages read what an issue's runs showed.
+      - "tests/campaign/observations.yml"
       # The Starlight project: config, components, styles, lockfile. Its
       # generated folders are gitignored and never trigger anything.
       - "website/**"