feat(discovery): blocked countries filter and smoke subprocess fixes

Add blockedCountries in Settings so pipeline discovery drops jobs whose
location mentions listed countries (existing discovered rows are kept).
Document the feature, fix smoke tsconfig inheritance for nested extractors,
and run smoke via an absolute-tsconfig wrapper.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/run-smoke-extractors.mjs

@@ -0,0 +1,17 @@
+import { spawnSync } from "node:child_process";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+const scriptsDir = path.dirname(fileURLToPath(import.meta.url));
+const repoRoot = path.join(scriptsDir, "..");
+const tsx = path.join(repoRoot, "node_modules", ".bin", "tsx");
+const tsconfig = path.join(scriptsDir, "tsconfig.smoke.json");
+const smokeScript = path.join(scriptsDir, "smoke-extractors.ts");
+
+const result = spawnSync(
+  tsx,
+  ["--tsconfig", tsconfig, smokeScript, ...process.argv.slice(2)],
+  { cwd: repoRoot, stdio: "inherit", env: process.env },
+);
+
+process.exit(result.status ?? 1);