docs(waitlist): add implementation TODOs summary + commit links to roadmap

docs/PRE_LAUNCH_SIGNUP_SYSTEM.md

@@ -292,7 +292,7 @@ User visits pre-launch page
   - Container: `waitlist`, partition key: `/email`
   - Also added 13 previously missing containers to `CONTAINER_DEFS`
 - [x] **2.5** Register routes in `src/server.ts` — [`2692c91`](https://github.com/saravanakumardb1/learning_ai_common_plat/commit/2692c91)
-- [x] **2.6** Write unit tests (45 tests passing) — _next commit_
+- [x] **2.6** Write unit tests (45 tests passing) — [`6a996cc`](https://github.com/saravanakumardb1/learning_ai_common_plat/commit/6a996cc)
   - File: `src/modules/waitlist/waitlist.test.ts`
   - Schema validation, email normalization, status transitions, route exports
 - [x] **2.7** Add admin role guard to all admin endpoints — [`2692c91`](https://github.com/saravanakumardb1/learning_ai_common_plat/commit/2692c91)
@@ -474,3 +474,37 @@ services/platform-service/src/modules/waitlist/
   - Con: adds friction, requires email delivery infrastructure
 - [ ] Should the product status transition be strictly sequential or allow admin override?
   - Current design: suggest validation but allow admin override. Document both options.
+
+---
+
+## 11. Implementation TODOs (Deferred — Needs Review)
+
+These TODOs were marked during implementation. They are **in the code as comments** and need your decision before wiring up.
+
+| #          | Location                                       | Description                                                                                                                                                                                                                                                                          | Blocker?                                                            |
+| ---------- | ---------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------- |
+| **TODO-1** | `routes.ts` — join endpoint                    | **CAPTCHA validation**: When `prelaunchConfig.captchaEnabled` is true, we need to verify `captchaToken` against the configured provider (Turnstile/hCaptcha/reCAPTCHA). Requires: provider API keys, HTTP call to verify endpoint. Currently skipped — signup works without CAPTCHA. | No — rate limiting is in place as interim protection                |
+| **TODO-2** | `routes.ts` — delete, invite, export endpoints | **Audit log wiring**: Admin actions (delete entry, batch invite, CSV export) should create audit log entries via the existing `audit/` module. Currently commented out — needs `auditRepo.create()` calls.                                                                           | No — actions work, just not logged                                  |
+| **TODO-3** | `routes.ts` — batch invite endpoint            | **Invitation code auto-generation**: Batch invite currently marks entries as `invited` but does NOT auto-generate invitation codes via the `invitations/` module. The `invitationCodeId` field stays empty. Need to call `invitations/repository.ts` `create()` for each entry.      | Yes — invited users won't have a code to redeem until this is wired |
+
+### Remaining Unchecked Roadmap Items
+
+| Task    | Phase                              | Status      | Notes                                                           |
+| ------- | ---------------------------------- | ----------- | --------------------------------------------------------------- |
+| 3.2     | Referral stats in stats endpoint   | Not started | Add referral-specific aggregations to `GET /api/waitlist/stats` |
+| 3.4     | Referral leaderboard endpoint      | Not started | Optional — `GET /public/waitlist/:productId/top-referrers`      |
+| 3.5     | Referral integration tests         | Not started | Circular/self-referral prevention tests                         |
+| 4.2     | Notifications email delivery       | Not started | Depends on email provider (SendGrid/SES/Azure Comms)            |
+| 4.3     | Invitation redemption → conversion | Not started | Hook `dispatchInvitationRedeemed` → update waitlist entry       |
+| 4.4     | Batch invite + conversion tests    | Not started | Depends on TODO-3                                               |
+| 5.1–5.4 | Admin dashboard UI                 | Not started | Waitlist management page, stats widget, config editor           |
+| 6.1–6.4 | Public signup page frontend        | Not started | Responsive signup form, confirmation, status check              |
+| 7.1–7.8 | Analytics & polish                 | Not started | Time series, CSV export, CAPTCHA, email delivery                |
+
+### Summary of Commits
+
+| Commit                                                                                  | Description                                                                                |
+| --------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------ |
+| [`66e657a`](https://github.com/saravanakumardb1/learning_ai_common_plat/commit/66e657a) | Phase 1: Product status lifecycle + prelaunchConfig types                                  |
+| [`2692c91`](https://github.com/saravanakumardb1/learning_ai_common_plat/commit/2692c91) | Phase 2: Waitlist module (types, repo, routes, webhooks, cosmos-init, server registration) |
+| [`6a996cc`](https://github.com/saravanakumardb1/learning_ai_common_plat/commit/6a996cc) | Tests (45 passing) + doc checkboxes + .env.example webhook vars                            |