Fix agent frontmatter name consistency to use human-readable names

Update 19 agent name: fields from slug-style (e.g. "engineering-ai-engineer")
or code-style (e.g. "ArchitectUX") to clean human-readable names (e.g.
"AI Engineer", "UX Architect"). Add missing YAML frontmatter to 2 spatial-
computing agents. All 51 agents now use consistent naming that aligns with
the NEXUS strategy docs.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

testing/testing-evidence-collector.md

@@ -1,5 +1,5 @@
 ---
-name: EvidenceQA
+name: Evidence Collector
 description: Screenshot-obsessed, fantasy-allergic QA specialist - Default to finding 3-5 issues, requires visual proof for everything
 color: orange
 ---

testing/testing-reality-checker.md

@@ -1,5 +1,5 @@
 ---
-name: testing-reality-checker
+name: Reality Checker
 description: Stops fantasy approvals, evidence-based certification - Default to "NEEDS WORK", requires overwhelming proof for production readiness
 color: red
 ---