resolve architecture review round 2: criticals, warnings, suggestions

- C-05: Add flowgraph-api.md with complete public API surface
- C-06: Document <Map> component in workflow-templates.md
- C-07: Specify Conditional else-branch behavior
- C-08: Add lifecycle/ownership section to reactive-execution.md
- C-09: Add consumer-integration.md end-to-end walkthrough
- W-02: Add reactive error boundary semantics (3 levels)
- W-03: Complete ReactiveContext interface definition
- W-04: Add template composition rules (8 rules)
- W-05: Document removeChild for both HostConfigs
- W-06: Document signal/effect disposal lifecycle
- W-07: Add ADR-004 (no schema version field)
- W-08: Add type compatibility depth/contract to analysis.md
- W-11: Add performance characteristics section
- S-01: Getting Started merged into consumer-integration.md
- S-02: Add flow diagrams for template rendering pipeline
- S-03: Add node status state machine diagram
- S-04: Add testing strategy section
- S-06: Validate source structure cross-references

Review round 2 fixes:
- Define TemplateNodeAttrs as alias for OperationNodeAttrs
- Document CallEventMapValue and CallResult types in schema.md
- Standardize CycleError naming (replace CircularDependencyError)
- Add function form to Map.over type definition
- Define Map aggregate completion/failure semantics
- Fix immutability claim for fromCallEvents
- Clarify edgeType storage alongside OperationEdgeAttrs
- Clarify WorkflowNode.status === statusMap (same Signal)
- Add component-to-tag mapping for WorkflowTag

docs/architecture/error-handling.md

@@ -1,6 +1,6 @@
 ---
 status: draft
-last_updated: 2026-05-19
+last_updated: 2026-05-20
 ---
 
 # Error Handling
@@ -115,7 +115,7 @@ class CycleError extends ConstructionError {
 
 Thrown when adding an edge would create a cycle. The `cycles` field contains the cycle paths that would be created.
 
-Note: Unlike `CircularDependencyError` in taskgraph (which is thrown by `topologicalOrder()`), `CycleError` is thrown by `addEdge()` during construction. Taskgraph allows cycles and detects them later; flowgraph prevents them at construction time.
+Note: `CycleError` is flowgraph's cycle error, thrown by `addEdge()` during construction. Taskgraph uses a different error name (`CircularDependencyError`, thrown by `topologicalOrder()`). The two are distinct errors for distinct contexts — flowgraph prevents cycles at construction time, taskgraph allows cycles and detects them later.
 
 ### ValidationError
 
@@ -236,7 +236,7 @@ The distinction between thrown errors and returned errors:
 | `validateGraph()` | Returns `GraphValidationError[]` | Graph issues are validations, not crashes |
 | `validateTemplate()` | Returns `AnyValidationError[]` | Template issues are validations, not crashes |
 | `analyzeTypeCompat()` | Returns `TypeCompatResult` (includes mismatches) | Type incompatibility is advisory, not blocking |
-| `topologicalOrder()` | Throws `CircularDependencyError` on cycles | No valid ordering exists from a cyclic graph |
+| `topologicalOrder()` | Throws `CycleError` on cycles | No valid ordering exists from a cyclic graph |
 
 This matches taskgraph's pattern: construction enforces invariants (throwing on violations), validation reports issues (returning error arrays).