fix build/distribution spec: npm deps not workspace, align configs with sibling projects, resolve review issues

- Replace workspace:* deps with published npm semver ranges (^0.34.49, ^0.1.0)
- Expand package.json: add description, publishConfig, scripts, engines,
  devDependencies, conditional exports with types/default for import+require
- Fix tsup entry names (path-prefixed like ujsx), add target: es2022,
  remove splitting:true (not used by sibling projects)
- Align tsconfig with sibling projects: add lib, noUncheckedIndexedAccess,
  noUnusedLocals, noUnusedParameters, erasableSyntaxOnly, etc.
- Expand vitest.config.ts with include, coverage, and path alias
- Clarify @preact/signals-core as direct dep (not just transitive via ujsx)
- Clarify @alkdev/pubsub is a consumer dependency, not flowgraph's dep
- Fix edge key convention: document composite key format for call graph's
  multi-edge-type scenario (triggered + depends_on between same pair)
- Align OperationEdgeAttrs field naming: use detail+mismatches consistently
  instead of compatibilityDetail
- Add InvalidInputError to error hierarchy (referenced in flowgraph-api but
  was missing)
- Fix undefined attrs.category reference in reactive-execution.md
- Remove internal drafting note from host-configs.md
- Fix ReactiveHostConfig constructor signature inconsistency across docs
- Constrain TemplateEdgeAttrs.edgeType to sequential|conditional only

docs/architecture/reactive-execution.md

@@ -47,7 +47,9 @@ class WorkflowReactiveRoot {
 private initializeSignals(): void {
   for (const node of this.graph.nodes()) {
     const attrs = this.graph.getNodeAttributes(node);
-    if (attrs.category !== "operation") continue;  // Skip structural nodes (already flattened)
+    // In the flattened DAG from GraphologyHostConfig, all nodes represent
+    // operations (structural containers like Sequential/Parallel are transparent
+    // and create no nodes). No filtering needed — every node gets a signal.
 
     const status = signal<NodeStatus>("idle");