decompose architecture into 38 atomic tasks across 12 parallel generations

Decompose the reviewed architecture specs into taskgraph-managed tasks:
- 2 setup tasks (project init, test infrastructure)
- 4 schema tasks (enums, node attrs, edge attrs, graph schemas)
- 1 error hierarchy task
- 6 graph tasks (FlowGraph class, 3 construction paths, queries, validation)
- 5 analysis tasks (type-compat, build-type-edges, ordering, template-validation, defaults)
- 5 component tasks (Operation, Sequential, Parallel, Conditional, Map)
- 2 host config tasks (GraphologyHostConfig, ReactiveHostConfig)
- 4 reactive tasks (WorkflowRoot, node-status, max-concurrency, retry-semantics)
- 3 review tasks (foundation, reactive-and-hosts, complete-library)
- 5 meta cluster tasks (schema, graph, component, reactive, analysis layers)
- 1 API exports task

Validated with taskgraph: zero cycles, 38 tasks, 12 parallel generations.
Critical path: 12 tasks through reactive execution layer.

tasks/schema-enums.md

@@ -0,0 +1,44 @@
+---
+id: schema/enums
+name: Define TypeBox categorical enum schemas and type aliases
+status: pending
+depends_on:
+  - setup/project-init
+scope: narrow
+risk: trivial
+impact: component
+level: implementation
+---
+
+## Description
+
+Define all categorical enum schemas using `Type.Union([Type.Literal(...)])` pattern per [schema.md](../docs/architecture/schema.md). Each enum gets a schema constant (PascalCase + `Enum` suffix) and a `Static<typeof>` type alias (PascalCase, no suffix). Also include the `Nullable` helper.
+
+The enums: `CallStatusEnum`, `NodeStatusEnum`, `OperationTypeEnum`, `EdgeTypeEnum`.
+
+## Acceptance Criteria
+
+- [ ] `src/schema/enums.ts` exports all four enum schemas and their type aliases
+- [ ] Each enum uses `Type.Union([Type.Literal("value"), ...])` pattern per typebox conventions
+- [ ] `CallStatusEnum`: `"pending" | "running" | "completed" | "failed" | "aborted"` with transitions documented in JSDoc
+- [ ] `NodeStatusEnum`: `"idle" | "waiting" | "ready" | "running" | "completed" | "failed" | "skipped" | "aborted"`
+- [ ] `OperationTypeEnum`: `"query" | "mutation" | "subscription"`
+- [ ] `EdgeTypeEnum`: `"triggered" | "depends_on" | "typed" | "sequential" | "conditional"`
+- [ ] Type aliases derived via `Static<typeof>`: `CallStatus`, `NodeStatus`, `OperationType`, `EdgeType`
+- [ ] Naming convention matches spec: `Enum` suffix on schema constants only, never on type aliases
+- [ ] `Nullable` helper exported: `const Nullable = <T extends TSchema>(schema: T) => Type.Union([schema, Type.Null()])`
+- [ ] `src/schema/index.ts` re-exports all schemas and types
+- [ ] Unit tests for each enum: `Value.Check()` validation, compile-time type alias verification
+
+## References
+
+- docs/architecture/schema.md — enum definitions, naming convention, nullable helper
+- docs/architecture/reactive-execution.md — NodeStatus semantics and transitions
+
+## Notes
+
+> To be filled by implementation agent
+
+## Summary
+
+> To be filled on completion