refactor(blox): namespace vertical-locked blocks; generalise focus-areas

- research-areas → focus-areas (general scope: services, programs,
  research themes, expertise). Metric fields refactored from hardcoded
  team_size/publications/funding into a generic
  `metrics: [{icon, value, label}]` array; legacy fields kept as a
  backcompat fallback so existing content renders identically.
- knowledge-categories → help-categories
- trending-questions → help-questions

The `help-` prefix matches public-facing help-center conventions and mirrors the existing `resume-` namespace
pattern for vertical-locked blocks. Aliases in
data/blox_aliases.yaml preserve backwards compatibility -
templates keep working without content edits.

modules/blox/data/blox_aliases.yaml

@@ -9,3 +9,9 @@ renames:
     new: resume-languages
   - old: skills
     new: resume-skills
+  - old: research-areas
+    new: focus-areas
+  - old: knowledge-categories
+    new: help-categories
+  - old: trending-questions
+    new: help-questions