feat(FN-1163): align command references with fn naming

- Update CLI command strings, help text, and project-resolution messaging to reference fn
- Sync core backup/store messaging and dashboard API/planning/subtask prompt examples with fn usage
- Refresh dashboard UI copy in settings, project detection, and PR guidance for consistent command naming
- Adjust CLI/dashboard tests and add a @gsxdsm/fusion changeset for the naming alignment patch

packages/cli/src/commands/dashboard.ts

@@ -840,7 +840,7 @@ export async function runDashboard(port: number, opts: { paused?: boolean; dev?:
     }
 
     console.log();
-    console.log(`  kb board`);
+    console.log(`  fn board`);
     console.log(`  ────────────────────────`);
     console.log(`  → http://localhost:${actualPort}`);
     console.log();