FN-6007: prevent duplicate GitHub issue imports and tracking issues

Prevent duplicate GitHub issue/task linkage from creating redundant imports and tracking issues.

- add shared duplicate-detection helpers that match imported GitHub issues by source metadata as well as source URLs
- switch CLI and dashboard GitHub import flows to inspect full task records and reuse the helper during single and batch imports
- remove redundant duplicate/refine tracking-issue creation calls from task workflow routes and add a patch changeset with regression coverage

Files changed:
 .changeset/fn-6007-fix-duplicate-github-issues.md  |  5 ++
 packages/cli/src/__tests__/extension.test.ts       | 68 ++++++++++++++++
 packages/cli/src/extension.ts                      | 24 ++++--
 .../src/__tests__/github-tracking-hook.test.ts     | 68 ++++++++++++++++
 .../dashboard/src/__tests__/routes-github.test.ts  | 73 ++++++++++++++++++
 .../src/__tests__/routes-tasks-ops.test.ts         | 90 +---------------------
 .../dashboard/src/routes/register-git-github.ts    | 24 ++++--
 .../src/routes/register-task-workflow-routes.ts    | 16 ----
 8 files changed, 254 insertions(+), 114 deletions(-)

Fusion-Task-Id: FN-6007

Fusion-Task-Lineage: a32ebb1d-efe4-4a52-be9a-fa3d3b5954bf

packages/cli/src/__tests__/extension.test.ts

@@ -2234,6 +2234,74 @@ describe.skipIf(!SHOULD_RUN_LEGACY_EXTENSION_INTEGRATION)("fn pi extension (lega
       });
     });
 
+    it("fn_task_import_github skips issues already imported via sourceIssue even when description was edited", async () => {
+      const store = new TaskStore(tmpDir);
+      await store.init();
+      await store.createTask({
+        title: "Existing imported issue",
+        description: "Edited description without source URL",
+        sourceIssue: {
+          provider: "github",
+          repository: "acme/demo",
+          externalIssueId: "1",
+          issueNumber: 1,
+          url: "https://github.com/acme/demo/issues/1",
+        },
+      });
+      store.close();
+
+      const tool = api.tools.get("fn_task_import_github")!;
+      vi.mocked(runGhJsonAsync).mockResolvedValueOnce([
+        {
+          number: 1,
+          title: "Issue one",
+          body: "First issue body",
+          html_url: "https://github.com/acme/demo/issues/1",
+        },
+      ] as never);
+
+      const result = await tool.execute("gh-2b", { ownerRepo: "acme/demo" }, undefined, undefined, makeCtx(tmpDir));
+
+      expect(result.content[0].text).toContain("Imported 0 tasks from acme/demo");
+      expect(result.details.createdTasks).toHaveLength(0);
+    });
+
+    it("fn_task_import_github_issue skips issues already imported via sourceIssue even when description was edited", async () => {
+      const store = new TaskStore(tmpDir);
+      await store.init();
+      const existing = await store.createTask({
+        title: "Existing imported issue",
+        description: "Edited description without source URL",
+        sourceIssue: {
+          provider: "github",
+          repository: "acme/demo",
+          externalIssueId: "1",
+          issueNumber: 1,
+          url: "https://github.com/acme/demo/issues/1",
+        },
+      });
+      store.close();
+
+      const tool = api.tools.get("fn_task_import_github_issue")!;
+      vi.mocked(runGhJsonAsync).mockResolvedValueOnce({
+        number: 1,
+        title: "Issue one",
+        body: "First issue body",
+        html_url: "https://github.com/acme/demo/issues/1",
+      } as never);
+
+      const result = await tool.execute(
+        "gh-2c",
+        { owner: "acme", repo: "demo", issueNumber: 1 },
+        undefined,
+        undefined,
+        makeCtx(tmpDir),
+      );
+
+      expect(result.details).toMatchObject({ skipped: true, existingTaskId: existing.id });
+      expect(result.content[0].text).toContain(existing.id);
+    });
+
     it("fn_task_browse_github_issues lists issues via gh api", async () => {
       const tool = api.tools.get("fn_task_browse_github_issues")!;
       vi.mocked(runGhJsonAsync).mockResolvedValueOnce([

packages/cli/src/extension.ts

@@ -442,6 +442,20 @@ function buildGitHubIssueSource(owner: string, repo: string, issue: { number: nu
   };
 }
 
+function isIssueAlreadyImported(
+  task: Pick<Task, "description" | "sourceIssue">,
+  owner: string,
+  repo: string,
+  issueNumber: number,
+  sourceUrl: string,
+): boolean {
+  const sourceIssue = task.sourceIssue;
+  return task.description.includes(sourceUrl)
+    || (sourceIssue?.provider === "github"
+      && sourceIssue.repository === `${owner}/${repo}`
+      && sourceIssue.issueNumber === issueNumber);
+}
+
 async function fetchGitHubIssueViaGh(
   owner: string,
   repo: string,
@@ -1274,12 +1288,12 @@ export default function kbExtension(pi: ExtensionAPI) {
       }
 
       const store = await getStore(ctx.cwd);
-      const existingTasks = await store.listTasks({ slim: true });
+      const existingTasks = await store.listTasks({ slim: false });
       const createdTasks: Array<{ id: string; title: string }> = [];
 
       for (const issue of issues) {
         const sourceUrl = issue.html_url;
-        const alreadyImported = existingTasks.some((task) => task.description.includes(sourceUrl));
+        const alreadyImported = existingTasks.some((task) => isIssueAlreadyImported(task, owner, repo, issue.number, sourceUrl));
         if (alreadyImported) {
           continue;
         }
@@ -1304,7 +1318,7 @@ export default function kbExtension(pi: ExtensionAPI) {
         await store.logEntry(task.id, "Imported from GitHub", sourceUrl);
         createdTasks.push({ id: task.id, title: task.title || issue.title });
 
-        existingTasks.push({ ...task, description });
+        existingTasks.push(task);
       }
 
       const summary = `✓ Imported ${createdTasks.length} tasks from ${owner}/${repo}`;
@@ -1358,11 +1372,11 @@ export default function kbExtension(pi: ExtensionAPI) {
 
       // Check if already imported
       const store = await getStore(ctx.cwd);
-      const existingTasks = await store.listTasks({ slim: true });
+      const existingTasks = await store.listTasks({ slim: false });
       const sourceUrl = issue.html_url;
 
       for (const task of existingTasks) {
-        if (task.description.includes(sourceUrl)) {
+        if (isIssueAlreadyImported(task, owner, repo, issueNumber, sourceUrl)) {
           return {
             content: [
               {