nx_tls13_server_session_emit_ee_alpn.nx

nx_tls13_server_session_emit_ee_alpn.nx -- TUTOR-BOOTSTRAP SCAFFOLD (Claude, authored under the B1 rung(3) ALPN-h2 SERVER workflow of the R4-H2 HTTP/2-transport ladder), NOT credited as team self-authoring. The ALPN-h2 SIBLING of the base 6th TLS server stone nx_tls13_server_session_emit_ee (runtime/nx_tls13_server_session_emit_ee.nx). The base stone emits an EMPTY EncryptedExtensions inner '08 00 00 02 00 00' (no extensions -> no ALPN negotiated). THIS variant emits the byte-exact ALPN-h2 EE inner so a sovereign h2 client (which advertises "h2" via tls13_ext_emit_alpn_h2_only) sees its protocol SELECTED: 08 00 00 0b 00 09 00 10 00 05 00 03 02 68 32 (15 bytes) HT_ENCRYPTED_EXTENSIONS = 0x08 body_len u24 = 0x00000b = 11 ext_list_len = 0x0009 = 9 (one ALPN EE ext, 9 wire bytes) ALPN EE ext = 00 10 00 05 00 03 02 68 32 ext_type 0x0010, ext_data_len 0x0005, protocol_name_list_len 0x0003, name_len 0x02, "h2" = 0x68 0x32 The trailing 9 ALPN bytes are NOT reinvented here: they are emitted BYTE-FOR- BYTE by the GREEN client emitter tls13_ext_emit_alpn_h2_only (runtime/nx_tls13_ext.nx:236, KAT '00 10 00 05 00 03 02 68 32' at :235), which we call into inner+6. The CLIENT'S tls13_ext_parse_alpn_selected recovers "h2" from exactly the trailing ext_data (00 03 02 68 32). NO-STRIP (rule 25): the base emit_ee + emit_ee_test are left BYTE-INTACT. This is a NEW path used only by the run_h2 server variant; the base server run keeps emitting the empty no-ext EE. Everything else is copied VERBATIM from the base stone: encrypt under server_hs_traffic_key/iv/server_seq via nx_tls13_record_encrypt_v2 (CT_HANDSHAKE), feed the 15 PLAINTEXT inner bytes (not the AEAD record) to nx_tls13_transcript_update, ++server_seq, advance EE_SENT -> CERT_SENT. BACK-FILL: the team RE-AUTHORS this from the DATA spec via the emitter-of-emitters (X-AUT-006c/e/f); this hand scaffold is the sanctioned one-time bootstrap only (meter-integrity, mirror nx_tls13_server_session_emit_ee.nx:1-22). Precondition: state == EE_SENT. Postcondition: state == CERT_SENT.