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/rename-task-dependencies-column.md

@@ -0,0 +1,34 @@
+---
+id: rename-task-dependencies-column
+name: Rename taskId to dependentTaskId in task_dependencies
+status: completed
+depends_on: []
+scope: single
+risk: trivial
+impact: isolated
+level: implementation
+---
+
+## Description
+
+**S16**: The column name `taskId` in `task_dependencies` is generic and could be confused as "this task" rather than "the dependent task." The paired column is `dependsOnTaskId`. Renaming `taskId` to `dependentTaskId` makes the FK direction unmistakable — `dependentTaskId` depends on `dependsOnTaskId`.
+
+## Acceptance Criteria
+
+- [ ] `tasks.md` uses `dependentTaskId` instead of `taskId` in the `task_dependencies` table spec
+- [ ] `table-reference.md` updated with the renamed column
+- [ ] All cross-references updated (FK targets, cascade entries)
+
+## References
+
+- docs/reviews/storage-architecture-review-2026-04-21.md#S16
+- docs/architecture/storage/tasks.md
+- docs/architecture/storage/table-reference.md
+
+## Notes
+
+> To be filled by implementation agent
+
+## Summary
+
+> To be filled on completion