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/add-missing-indexes-observability.md

@@ -0,0 +1,44 @@
+---
+id: add-missing-indexes-observability
+name: Add Missing Indexes — Call Graph & Observability Domain
+status: completed
+depends_on: [add-call-graph-edges-indexes-cascades]
+scope: narrow
+risk: low
+impact: component
+level: implementation
+---
+
+## Description
+
+W03 (partial): Add missing indexes for call graph tables. These are closely related to C10 (call graph edges missing indexes and cascade documentation) — the cascade documentation should be resolved first, then indexes added here.
+
+Missing indexes:
+- `call_graph_nodes`: `idx_call_graph_nodes_created_at` on `(createdAt)` — time-range queries
+- `call_graph_nodes`: `idx_call_graph_nodes_operation_created` on `(operationId, createdAt)` — operation + time queries
+- `call_graph_edges`: `idx_call_graph_edges_source_id` on `(sourceId)` — graph traversal (children)
+- `call_graph_edges`: `idx_call_graph_edges_target_id` on `(targetId)` — graph traversal (parents)
+
+Note: The edge indexes are also called out in C10. This task focuses on adding them to the spec docs; C10's critical task resolves the cascade documentation and `parentRequestId` ambiguity.
+
+## Acceptance Criteria
+
+- [ ] `table-reference.md` indexes section includes all four call graph indexes
+- [ ] `call-graph.md` per-domain doc references the new indexes
+- [ ] Index purposes documented (graph traversal for edges, time-range/compound for nodes)
+- [ ] Cross-reference to C10 resolution noted if cascade entries were already added
+
+## References
+
+- docs/reviews/storage-architecture-review-2026-04-21.md#W03
+- docs/reviews/storage-architecture-review-2026-04-21.md#C10
+- docs/architecture/storage/table-reference.md
+- docs/architecture/storage/call-graph.md
+
+## Notes
+
+> To be filled by implementation agent
+
+## Summary
+
+> To be filled on completion