Answer 3.4 binds with sc_interface_version and cover TLS with tests

todo.md

@@ -5,7 +5,7 @@ rules there constrain every item below.
 
 ## Status
 
-The rewrite is **feature complete and green**: 137 tests, lint and typecheck clean, verified on Node
+The rewrite is **feature complete and green**: 144 tests, lint and typecheck clean, verified on Node
 18, 20, 22 and 24. What is left is release work and a few things worth adding before or after 1.0.0.
 
 ```bash
@@ -74,12 +74,6 @@ Every defect listed in the AGENTS.md table has a regression test naming the beha
 - [ ] **In-flight sends across a reconnect.** They currently fail with "Session closed before a
       response arrived" and the caller retries. Re-queueing them automatically would be friendlier
       but risks duplicate delivery, so it needs a decision before it is built.
-- [ ] **The server never returns the `sc_interface_version` TLV.** The 3.4 spec has an ESME read its
-      absence from a bind response as "this SMSC does not support optional parameters", and ours
-      does send DLR TLVs. Returning it has to be conditional: a peer that declared below 0x34 must
-      not be sent optional parameters at all.
-- [ ] **TLS is untested.** The code path is right (`tls.connect` / `tls.createServer`, options
-      passed through) but no test exercises a handshake. Needs a self-signed certificate fixture.
 - [ ] **`submit_multi` and the broadcast commands** encode and decode, but nothing exercises them
       end to end. The interop suite is the natural place.
 - [ ] **Move to TypeScript 7** once `typescript-eslint` supports it; `renovate.json` pins TypeScript