fix: make maintainer tool output actionable

--emulator accepts a buildbot core name from a profile's cores:, and a
mistyped target gets the closest names instead of every target. diff_truth
shows destinations and reports unpaired entries as evidence, not removals.
The verify summary counts discrepancies, a shared destination names both
systems, a truth hash conflict names both cores, and pipeline steps carry
their place in the real run instead of N/8. Every GitHub API caller takes
the token from github_token(), which falls back to gh auth token.

scripts/generate_pack.py

@@ -3087,8 +3087,10 @@ def _main(held: contextlib.ExitStack) -> None:
             )
         return
     if args.list:
+        # Archived platforms build like the others but have no release pack.
+        active = set(list_registered_platforms(args.platforms_dir))
         for p in list_platforms(args.platforms_dir):
-            print(p)
+            print(p if p in active else f"{p} (archived)")
         return
     if args.list_emulators:
         list_emulator_profiles(args.emulators_dir)