chore(agents): sync agent configs — model updates to nemotron-3-super

- Update agent model assignments (nemotron-3-ultra -> nemotron-3-super) across .kilo/agents, kilo-meta.json, kilo.jsonc, capability-index.yaml
- Sync agent descriptions in KILO_SPEC.md

.kilo/agents/stakeholder-bridge.md

@@ -1,7 +1,7 @@
 ---
 description: Translates technical outputs into business language for non-technical stakeholders, generates executive summaries and progress reports
 mode: subagent
-model: ollama-cloud/nemotron-3-ultra
+model: ollama-cloud/nemotron-3-super
 variant: thinking
 color: "#DC2626"
 permission: