fix: give the common-skill buttons their own label and tagline

The seven selector buttons were rendering `kind` and `use`, which belong
to the detail panel. ponytail's button read "SIMPLIFICATION INSTINCT" and
a full paragraph of prose where today's page reads "SIMPLIFY" and
"minimum code that holds". English was wrong, not just Portuguese
missing, on all seven.

Those two lines are not in `interactiveCopy`, which is why task 05b had
nothing to migrate them from: the English lives in the
`full-guide/index.html` markup and the Portuguese in `translations.pt`.
Adds `label` and `tagline` to the `commonSkills` schema and to all seven
entries, both taken verbatim from those two sources, and points the
buttons at them. The panel keeps reading `kind` and `use`.

This closes the last 13 of the 102 `translations.pt` entries. Coverage in
`dist/full-guide/index.html` is now 102 of 102.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/content/commonSkills/caveman.json

@@ -13,5 +13,7 @@
     "en": "Drop the style for security warnings, irreversible actions, and sequences where terse wording can be misread.",
     "pt": "Abandone o estilo em alertas de segurança, ações irreversíveis e sequências onde concisão pode causar erro."
   },
-  "source": "https://github.com/JuliusBrussee/caveman/blob/3b74643f4d910f496babd4e634b1ba7168816f14/skills/caveman/SKILL.md"
+  "source": "https://github.com/JuliusBrussee/caveman/blob/3b74643f4d910f496babd4e634b1ba7168816f14/skills/caveman/SKILL.md",
+  "label": { "en": "COMMUNICATE", "pt": "COMUNICAR" },
+  "tagline": { "en": "signal without filler", "pt": "sinal sem excesso" }
 }