chore: add kiro spec-driven tooling and steering docs

Add the Kiro-style agentic SDLC tooling used to drive this project: the
.opencode/skills/kiro-* skill set (discovery, spec init/requirements/design/
tasks, validation, implementation, review, steering), the .kiro/settings
templates, and AGENTS.md describing the workflow. Update the spec docs
(assessment/design/requirements/tasks) to current state.

Scope tests/test_opencode_skills.py to the project's own openultrasast-*
skills so the third-party kiro-* tooling (which uses a different frontmatter
convention) no longer breaks the frontmatter check.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

.kiro/settings/templates/steering-custom/deployment.md

@@ -0,0 +1,54 @@
+# Deployment Standards
+
+[Purpose: safe, repeatable releases with clear environment and pipeline patterns]
+
+## Philosophy
+- Automate; test before deploy; verify after deploy
+- Prefer incremental rollout with fast rollback
+- Production changes must be observable and reversible
+
+## Environments
+- Dev: fast iteration; debugging enabled
+- Staging: mirrors prod; release validation
+- Prod: hardened; monitored; least privilege
+
+## CI/CD Flow
+```
+Code → Test → Build → Scan → Deploy (staged) → Verify
+```
+Principles:
+- Fail fast on tests/scans; block deploy
+- Artifact builds are reproducible (lockfiles, pinned versions)
+- Manual approval for prod; auditable trail
+
+## Deployment Strategies
+- Rolling: gradual instance replacement
+- Blue-Green: switch traffic between two pools
+- Canary: small % users first, expand on health
+Choose per risk profile; document default.
+
+## Zero-Downtime & Migrations
+- Health checks gate traffic; graceful shutdown
+- Backwards-compatible DB changes during rollout
+- Separate migration step; test rollback paths
+
+## Rollback
+- Keep previous version ready; automate revert
+- Rollback faster than fix-forward; document triggers
+
+## Configuration & Secrets
+- 12-factor config via env; never commit secrets
+- Secret manager; rotate; least privilege; audit access
+- Validate required env vars at startup
+
+## Health & Monitoring
+- Endpoints: `/health`, `/health/live`, `/health/ready`
+- Monitor latency, error rate, throughput, saturation
+- Alerts on SLO breaches/spikes; tune to avoid fatigue
+
+## Incident Response & DR
+- Standard playbook: detect → assess → mitigate → communicate → resolve → post-mortem
+- Backups with retention; test restore; defined RPO/RTO
+
+---
+_Focus on rollout patterns and safeguards. No provider-specific steps._