chore(agents): sync agent configs, models, capability index; cleanup junk

- Update agent model assignments (minimax/glm -> nemotron-3-ultra, kimi-k2.7-code, qwen3.5:397b) in .kilo/agents, kilo-meta.json, kilo.jsonc, capability-index.yaml
- Update orchestrator/agent prompts (complexity fast-path, verification tests, close-loop audit)
- Add .kilo/KILO_SPEC.md (Kilo Code specification reference)
- AGENTS.md: consolidate smartadmin agent rows
- Remove screenshot-dash.cjs (unused, contained hardcoded admin token); gitignore it
- Remove empty .kilo/milestones/

.gitignore

@@ -23,3 +23,4 @@ db/*.db-shm
 
 # Production backups (contain secrets + DB snapshots — never commit)
 production-backup/
+screenshot-dash.cjs