Setup repo: migrate architecture specs, code stubs, and tasks from alkhub_ts

Copy architecture docs, ADRs, storage domain specs, research, reviews,
and 56 storage architecture tasks from the alkhub_ts monorepo. Adapt for
standalone @alkdev/hub repo structure (src/ not packages/hub/).

Sanitize all sensitive information:
- Replace private IPs (10.0.0.1) with localhost defaults
- Remove internal server hostnames (dev1, ns528096)
- Replace /workspace/ private paths with npm package references
- Remove hardcoded credentials from examples
- Rewrite infrastructure.md without private network details

Add Deno project scaffolding: deno.json (pinned deps), .gitignore,
AGENTS.md, entry point. Migrate existing code stubs (crypto, config
types, logger) with updated import paths.

tasks/architecture/storage/index-strategy.md

@@ -0,0 +1,32 @@
+---
+id: index-strategy
+name: Index Strategy
+status: completed
+depends_on: [add-missing-indexes-identity, add-missing-indexes-sessions, add-missing-indexes-observability, add-partial-indexes, fix-path-index-locale]
+scope: moderate
+risk: low
+impact: component
+level: review
+---
+
+## Description
+
+All index-related tasks. This group ensures complete index coverage across the storage layer — covering missing indexes for identity, sessions, and observability tables, partial indexes for common query patterns, and fixing the path index locale issue. Index decisions are low-risk but high-impact for query performance.
+
+## Acceptance Criteria
+
+- [ ] All dependent tasks are completed
+- [ ] Cross-references between completed tasks are consistent
+- [ ] No remaining contradictions in the covered domain
+
+## References
+
+- docs/reviews/storage-architecture-review-2026-04-21.md
+
+## Notes
+
+> To be filled by implementation agent
+
+## Summary
+
+> To be filled on completion