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/operation-graph.md

@@ -1,6 +1,6 @@
 ---
 status: draft
-last_updated: 2026-05-19
+last_updated: 2026-05-20
 ---
 
 # Operation Graph (Static)
@@ -113,7 +113,7 @@ The `typeCompat` analysis function determines compatibility. Edges where compati
 
 The operation graph validates:
 
-1. **Cycle detection** — throws `CircularDependencyError` if any cycle exists. Unlike taskgraph (which allows cycles and detects them via `hasCycles()`), flowgraph enforces acyclicity at construction time. A cycle in the operation graph means an operation's output feeds back into its own input, which is a design error.
+1. **Cycle detection** — throws `CycleError` if any cycle exists. Unlike taskgraph (which allows cycles and detects them via `hasCycles()`), flowgraph enforces acyclicity at construction time. A cycle in the operation graph means an operation's output feeds back into its own input, which is a design error.
 
 2. **Dangling references** — edges that reference operations not in the graph are structural errors. `addTypedEdge` throws `OperationNotFoundError` if either endpoint doesn't exist.