feat(FN-1216): rename extension tools to fn_* across CLI and docs

- Rename all pi extension tool registrations from kb_* to fn_* across task, mission, and agent tool families
- Update extension and skill-sync tests plus Fusion skill docs/workflows to assert and document the new fn_* tool names
- Align product-identity strings across core, dashboard, and CLI references, including GitHub import examples, User-Agent headers, and terminal TERM_PROGRAM
- Add a @gsxdsm/fusion minor changeset describing the extension tool-prefix rename

packages/cli/src/commands/task.ts

@@ -695,7 +695,7 @@ export async function runTaskImportGitHubInteractive(
   const match = ownerRepo.match(/^([^/]+)\/([^/]+)$/);
   if (!match) {
     console.error(`Invalid owner/repo format: ${ownerRepo}`);
-    console.error(`Expected format: owner/repo (e.g., dustinbyrne/kb)`);
+    console.error(`Expected format: owner/repo (e.g., dustinbyrne/fusion)`);
     process.exit(1);
   }
 
@@ -861,7 +861,7 @@ export async function fetchGitHubIssues(
   const headers: Record<string, string> = {
     Accept: "application/vnd.github+json",
     "X-GitHub-Api-Version": "2022-11-28",
-    "User-Agent": "kb-cli/1.0",
+    "User-Agent": "fn/1.0",
   };
 
   if (token) {
@@ -913,7 +913,7 @@ export async function runTaskImportFromGitHub(
   const match = ownerRepo.match(/^([^/]+)\/([^/]+)$/);
   if (!match) {
     console.error(`Invalid owner/repo format: ${ownerRepo}`);
-    console.error(`Expected format: owner/repo (e.g., dustinbyrne/kb)`);
+    console.error(`Expected format: owner/repo (e.g., dustinbyrne/fusion)`);
     process.exit(1);
   }