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-caller-account-id.md

@@ -0,0 +1,36 @@
+---
+id: add-caller-account-id
+name: Add callerAccountId to Call Graph Nodes
+status: completed
+depends_on: []
+scope: narrow
+risk: low
+impact: component
+level: implementation
+---
+
+## Description
+
+W19: `call_graph_nodes.identity` stores `{ id, scopes, resources }` as a JSONB snapshot, but there's no FK to `accounts.id`. Querying "all calls made by account X" requires JSONB containment, which is slow without a GIN index.
+
+Add a `callerAccountId` text column with FK → accounts.id (SET NULL) for efficient querying, or add a GIN index on `identity` if JSONB queries are the intended access pattern.
+
+## Acceptance Criteria
+
+- [ ] `call-graph.md` adds `callerAccountId` column (text, nullable, FK → accounts.id, ON DELETE SET NULL), OR
+- [ ] Alternative documented: GIN index on `identity` column with justification
+- [ ] If `callerAccountId` added: `table-reference.md` cascade table updated with the new FK
+- [ ] Query pattern documented: "all calls by account X" uses `callerAccountId`
+
+## References
+
+- docs/reviews/storage-architecture-review-2026-04-21.md#W19
+- docs/architecture/storage/call-graph.md:20
+
+## Notes
+
+> To be filled by implementation agent
+
+## Summary
+
+> To be filled on completion