Task #2: MVP Foundation — injectable services, DB schema, smoke test

DB schema
- jobs and invoices tables added to lib/db/src/schema/
- schema barrel updated (jobs, invoices, conversations, messages)
- pnpm --filter @workspace/db run push applied successfully

LNbitsService (artifacts/api-server/src/lib/lnbits.ts)
- Injectable class accepting optional { url, apiKey } config
- Falls back to LNBITS_URL / LNBITS_API_KEY env vars
- Auto-detects stub mode when credentials are absent; logs warning
- createInvoice() -> { paymentHash, paymentRequest }
- checkInvoicePaid() -> boolean
- stubMarkPaid() helper for dev/test flows
- Real LNbits REST v1 calls wired behind the stub guard

AgentService (artifacts/api-server/src/lib/agent.ts)
- Injectable class with configurable evalModel / workModel
- evaluateRequest(text) -> { accepted: boolean, reason: string }
  uses claude-haiku-4-5; strips markdown fences before JSON parse
- executeWork(text) -> { result: string } uses claude-sonnet-4-6
- Wired via Replit Anthropic AI Integration (no user API key)

PricingService (artifacts/api-server/src/lib/pricing.ts)
- Injectable class with configurable fee/bucket thresholds
- calculateEvalFeeSats() -> 10 sats (fixed)
- calculateWorkFeeSats(text) -> 50/100/250 by char-length bucket
- Zero LLM involvement; fully deterministic

Smoke test (scripts/src/smoke.ts)
- pnpm --filter @workspace/scripts run smoke
- Verifies LNbits stub: create, check unpaid, mark paid, check paid
- Verifies Anthropic: evaluateRequest round-trip
- Both checks passed

replit.md
- Documented required (LNBITS_URL, LNBITS_API_KEY) and auto-provisioned secrets
- Stub-mode behaviour explained

scripts/src/smoke.ts

@@ -0,0 +1,46 @@
+/**
+ * Smoke test: confirms LNbitsService and AgentService are reachable.
+ * Run: pnpm --filter @workspace/scripts run smoke
+ */
+import { LNbitsService } from "../../artifacts/api-server/src/lib/lnbits.ts";
+import { AgentService } from "../../artifacts/api-server/src/lib/agent.ts";
+
+async function smokeLnbits(): Promise<void> {
+  const svc = new LNbitsService();
+  const invoice = await svc.createInvoice(1, "smoke-test");
+  console.log("✓ LNbits createInvoice:", invoice.paymentHash.slice(0, 16), "...");
+
+  const paidBefore = await svc.checkInvoicePaid(invoice.paymentHash);
+  console.log("✓ LNbits checkInvoicePaid (unpaid, expect false):", paidBefore);
+
+  if (svc.stubMode) {
+    svc.stubMarkPaid(invoice.paymentHash);
+    const paidAfter = await svc.checkInvoicePaid(invoice.paymentHash);
+    console.log("✓ LNbits checkInvoicePaid (after stub mark, expect true):", paidAfter);
+  }
+}
+
+async function smokeAnthropic(): Promise<void> {
+  const svc = new AgentService();
+  const evalResult = await svc.evaluateRequest("What is 2 + 2?");
+  console.log("✓ AgentService evaluateRequest:", JSON.stringify(evalResult));
+}
+
+(async () => {
+  console.log("--- Timmy smoke test ---");
+  try {
+    await smokeLnbits();
+  } catch (err) {
+    console.error("✗ LNbits smoke failed:", err);
+    process.exitCode = 1;
+  }
+  try {
+    await smokeAnthropic();
+  } catch (err) {
+    console.error("✗ Anthropic smoke failed:", err);
+    process.exitCode = 1;
+  }
+  if (!process.exitCode) {
+    console.log("--- All smoke checks passed ---");
+  }
+})();