FN-6137: convert PR lifecycle built-in to fragment

Convert the built-in PR lifecycle into a reusable fragment instead of a selectable task workflow.

- mark builtin:pr-workflow as a fragment and exclude fragments from default-enabled built-ins
- hide built-in fragments from the General settings workflow toggles
- update core and dashboard tests to assert fragment behavior and reject task selection of the PR lifecycle fragment
- add a changeset for the published CLI package

Files changed:
 .changeset/pr-lifecycle-fragment.md                |  5 +++++
 .../core/src/__tests__/builtin-workflows.test.ts   | 24 ++++++++++++++++------
 packages/core/src/builtin-workflows.ts             |  7 ++++---
 packages/core/src/store.ts                         |  2 +-
 .../__tests__/WorkflowNodeEditor.test.tsx          |  3 ++-
 .../settings/sections/GeneralSection.tsx           |  4 +++-
 6 files changed, 33 insertions(+), 12 deletions(-)

Fusion-Task-Id: FN-6137

Fusion-Task-Lineage: d959ba3b-2e50-4c9b-a1fa-161776939403

.changeset/pr-lifecycle-fragment.md

@@ -0,0 +1,5 @@
+---
+"@runfusion/fusion": minor
+---
+
+Convert the built-in PR lifecycle from a selectable task workflow into a reusable workflow-editor fragment template.

packages/core/src/__tests__/builtin-workflows.test.ts

@@ -16,17 +16,16 @@ import { createTaskStoreTestHarness } from "./store-test-helpers.js";
 const EXECUTE_NODE_MAX_RETRIES = 2;
 
 describe("built-in workflows", () => {
-  // Graph-only built-ins (step inversion, KTD-9) model branching/foreach/rework
-  // structure the linear compiler cannot lower to a step list — they run only
-  // under the workflow graph executor. They still must parse as valid IR.
-  const GRAPH_ONLY_BUILTIN_IDS = new Set(["builtin:stepwise-coding", "builtin:pr-workflow"]);
+  // Non-compiler built-ins model graph-only node kinds or reusable fragments the
+  // linear compiler cannot lower to a step list. They still must parse as valid IR.
+  const NON_COMPILABLE_BUILTIN_IDS = new Set(["builtin:stepwise-coding", "builtin:pr-workflow"]);
 
   it("every built-in has a valid IR; linear built-ins compile without error", () => {
     expect(BUILTIN_WORKFLOWS.length).toBeGreaterThanOrEqual(4);
     for (const wf of BUILTIN_WORKFLOWS) {
       expect(isBuiltinWorkflowId(wf.id)).toBe(true);
       expect(() => parseWorkflowIr(wf.ir)).not.toThrow();
-      if (!GRAPH_ONLY_BUILTIN_IDS.has(wf.id)) {
+      if (!NON_COMPILABLE_BUILTIN_IDS.has(wf.id)) {
         expect(() => compileWorkflowToSteps(wf.ir)).not.toThrow();
       }
     }
@@ -51,6 +50,8 @@ describe("built-in workflows", () => {
   it("includes the PR lifecycle built-in wiring the PR nodes end to end (U9)", () => {
     const pr = getBuiltinWorkflow("builtin:pr-workflow");
     expect(pr).toBeDefined();
+    expect(pr!.kind).toBe("fragment");
+    expect(BUILTIN_WORKFLOWS.some((workflow) => workflow.id === "builtin:pr-workflow")).toBe(true);
     const ir = parseWorkflowIr(pr!.ir);
     if (ir.version !== "v2") throw new Error("expected v2");
 
@@ -143,7 +144,11 @@ describe("built-in workflows", () => {
     expect(getBuiltinWorkflow("builtin:coding")?.ir).toBe(BUILTIN_CODING_WORKFLOW_IR);
     expect(getBuiltinWorkflow("builtin:coding")?.ir).toBe(BUILTIN_CODING_WORKFLOW_IR);
     expect(BUILTIN_WORKFLOWS.find((workflow) => workflow.id === "builtin:coding")?.ir).toBe(BUILTIN_CODING_WORKFLOW_IR);
-    expect(defaultEnabledBuiltinWorkflowIds()).toEqual(BUILTIN_WORKFLOWS.map((workflow) => workflow.id));
+    expect(defaultEnabledBuiltinWorkflowIds()).toEqual(
+      BUILTIN_WORKFLOWS.filter((workflow) => workflow.kind !== "fragment").map((workflow) => workflow.id),
+    );
+    expect(defaultEnabledBuiltinWorkflowIds()).not.toContain("builtin:pr-workflow");
+    expect(getBuiltinWorkflow("builtin:pr-workflow")!.kind).toBe("fragment");
     expect(defaultEnabledBuiltinWorkflowIds().slice(0, 5)).toEqual([
       "builtin:coding",
       "builtin:quick-fix",
@@ -295,5 +300,12 @@ describe("built-in workflows", () => {
       await store.selectTaskWorkflow(task.id, "builtin:compound-engineering");
       expect(store.getTaskWorkflowSelection(task.id)?.workflowId).toBe("builtin:compound-engineering");
     });
+
+    it("rejects selecting the PR lifecycle fragment for a task", async () => {
+      const task = await store.createTask({ description: "T", enabledWorkflowSteps: [] });
+      await expect(store.selectTaskWorkflow(task.id, "builtin:pr-workflow")).rejects.toThrow(
+        "is a fragment and cannot be selected for a task",
+      );
+    });
   });
 });

packages/core/src/builtin-workflows.ts

@@ -15,7 +15,7 @@ export function isBuiltinWorkflowId(id: string): boolean {
 }
 
 export function defaultEnabledBuiltinWorkflowIds(): string[] {
-  return BUILTIN_WORKFLOWS.map((workflow) => workflow.id);
+  return BUILTIN_WORKFLOWS.filter((workflow) => workflow.kind !== "fragment").map((workflow) => workflow.id);
 }
 
 export function isBuiltinWorkflowEnabled(id: string, enabledIds?: readonly string[]): boolean {
@@ -69,7 +69,8 @@ function linear(spec: BuiltinSpec): WorkflowDefinition {
     id: spec.id,
     name: spec.name,
     description: spec.description,
-    // Built-ins are always selectable workflows, never fragments (KTD-1).
+    // Linear built-ins remain selectable workflows; catalog entries authored
+    // directly below may opt into fragment kind when they are palette templates.
     kind: "workflow",
     ir,
     layout,
@@ -215,7 +216,7 @@ export const BUILTIN_WORKFLOWS: WorkflowDefinition[] = [
     name: "PR lifecycle (built-in)",
     description:
       "The unified PR lifecycle as graph nodes: create the PR, await review, respond to changes (bounded rework loop), gate on auto-merge, then merge — with GitHub reconciliation advancing the await holds. Requires the workflow graph executor.",
-    kind: "workflow",
+    kind: "fragment",
     ir: BUILTIN_PR_WORKFLOW_IR,
     layout: {
       start: { x: 60, y: 160 },

packages/core/src/store.ts

@@ -13299,7 +13299,7 @@ ${stepsSection}`;
 
   /** Read (and cache) the full merged workflow-definition set, oldest first.
    *  Built-in templates lead the list and cannot be edited/deleted; built-ins
-   *  are always kind "workflow". */
+   *  may be selectable workflows or reusable fragments. */
   private async readAllWorkflowDefinitions(): Promise<WorkflowDefinition[]> {
     if (this.workflowDefinitionsCache) return this.workflowDefinitionsCache;
     const rows = this.db.prepare("SELECT * FROM workflows ORDER BY createdAt ASC").all() as Array<{

packages/dashboard/app/components/__tests__/WorkflowNodeEditor.test.tsx

@@ -169,7 +169,7 @@ function builtinDef(): WorkflowDefinition {
 function builtinPrDef(): WorkflowDefinition {
   return {
     id: "builtin:pr-workflow",
-    kind: "workflow",
+    kind: "fragment",
     name: "PR lifecycle (built-in)",
     description: "Ships with Fusion",
     ir: BUILTIN_PR_WORKFLOW_IR,
@@ -271,6 +271,7 @@ describe("workflow-flow-mapping", () => {
     expect(BUILTIN_WORKFLOWS.map((workflow) => workflow.id).sort()).toEqual(
       expect.arrayContaining(["builtin:coding", "builtin:stepwise-coding", "builtin:pr-workflow"]),
     );
+    expect(BUILTIN_WORKFLOWS.find((workflow) => workflow.id === "builtin:pr-workflow")?.kind).toBe("fragment");
 
     for (const workflow of BUILTIN_WORKFLOWS) {
       edgeRenderableAssertion(workflow);

packages/dashboard/app/components/settings/sections/GeneralSection.tsx

@@ -48,7 +48,9 @@ export function GeneralSection({
     fetchWorkflows(projectId, { includeDisabledBuiltins: true })
       .then((workflows) => {
         if (!cancelled) {
-          setBuiltinWorkflows(workflows.filter((workflow) => workflow.id.startsWith("builtin:")));
+          setBuiltinWorkflows(
+            workflows.filter((workflow) => workflow.id.startsWith("builtin:") && workflow.kind !== "fragment"),
+          );
         }
       })
       .catch(() => {