feat: add WiFi companion radio env for LilyGo T3-S3 V1

[adradr]

Summary

Adds LilyGo_T3S3_sx1262_companion_radio_wifi — a WiFi companion radio variant for the LilyGo T3-S3 V1 board. The env block is a 1:1 mirror of Heltec_v3_companion_radio_wifi, just swapping the extends = reference. No source code changes.

Also enables the _companion_radio_wifi suffix in build.sh's companion release loop, which has the side effect of starting to ship WiFi binaries for every board that already has a _companion_radio_wifi env upstream but isn't currently included in the companion-vX.Y.Z release tag (see "Side effect" below).

Refs:

• Fills the gap explicitly noted in Add support T3S3 v1.2 (SX1726) #387: "Could potentially have a wifi companion mode as well but didn't add it."
• Addresses the use case described in open issue LilygoT3-S3 BLE companion firmware. meshcore-py /meshcore-cli able to start connection, but serial does not answers. #1134 (T3-S3 BLE companion serial-no-response → user explicitly asks for a WiFi alternative).

Motivation

The T3-S3 V1 (ESP32-S3 + SX1262 + SSD1306 OLED) is structurally identical to the Heltec V3 from the WiFi companion stack's perspective — same MCU family, same radio, same display. The WiFi runtime path (#ifdef WIFI_SSID in examples/companion_radio/main.cpp and examples/companion_radio/ui-new/UITask.cpp) already ships and is exercised by Heltec_v3_companion_radio_wifi, RAK_3112_companion_radio_wifi, T_Beam_S3_Supreme_SX1262_companion_radio_wifi, and others. T3-S3 owners are the largest LilyGo group without a WiFi build today.

Changes

File	Lines	What
variants/lilygo_t3s3/platformio.ini	+24	New [env:LilyGo_T3S3_sx1262_companion_radio_wifi] block. No source code changes, no custom partition CSV, no upload_flags override, no display/board hardware definitions to add — all inherited from the existing [LilyGo_T3S3_sx1262] base block.
build.sh	+1	build_all_firmwares_by_suffix "_companion_radio_wifi" inside build_companion_firmwares(). Mirrors the existing _usb and _ble lines.

Total: 2 files, 25 lines, 0 source code changes.

Build sizes (default board partition, no override needed):

RAM:   51.1% (167,476 / 327,680 B)
Flash: 77.1% (1,010,497 / 1,310,720 B)   ← fits in default.csv's 1.25 MB app slot

Test plan

• Compiles cleanly with stock default.csv partition (no override needed).
• Flashed to LilyGo T3-S3 V1 hardware (433 MHz SX1262 variant).
• Device boots, joins WiFi (DHCP), OLED shows IP on the home page.
• TCP server reachable on port 5000 from the LAN.
• MeshCore companion protocol works end-to-end over TCP — verified by sending APP_START (0x01) and DEVICE_QUERY (0x16 0x03), receiving valid PACKET_SELF_INFO and PACKET_DEVICE_INFO.
• LoRa stack unaffected — position prefs survived, RF chip still functional.

Side effect — build.sh blast radius

The added build_all_firmwares_by_suffix "_companion_radio_wifi" line is upstream of any _wifi env. After this lands, the next companion-vX.Y.Z tag will start producing release binaries for the following WiFi envs that are already in the tree but currently silently skipped by the release loop:

Heltec_v2_companion_radio_wifi
Heltec_v3_companion_radio_wifi
Heltec_v4_companion_radio_wifi
Heltec_v4_tft_companion_radio_wifi
Heltec_WSL3_companion_radio_wifi
heltec_tracker_v2_companion_radio_wifi
LilyGo_TBeam_1W_companion_radio_wifi
LilyGo_TLora_V2_1_1_6_companion_radio_wifi
LilyGo_T3S3_sx1262_companion_radio_wifi     ← new in this PR
nibble_screen_connect_companion_radio_wifi
RAK_3112_companion_radio_wifi
Station_G2_companion_radio_wifi
T_Beam_S3_Supreme_SX1262_companion_radio_wifi
ThinkNode_M2_companion_radio_wifi
ThinkNode_M5_companion_radio_wifi
Xiao_C3_companion_radio_wifi
Xiao_S3_WIO_companion_radio_wifi

If maintainers prefer to land the build.sh line separately so the blast radius can be sanity-checked independently of this T3-S3 env, happy to split into two PRs.

Out of scope (acknowledged)

I'm aware of in-flight work that may eventually replace or supersede the compile-time WIFI_SSID / WIFI_PWD pattern:

• feat: Add companion WiFi CLI #2217 (CLI WiFi config persisted in NodePrefs)
• WifiManager to replace hardcoded ssid/password for ESP wifi companions #1648 (WiFiManager-based provisioning)
• Adding code to make wifi work better on companions #1888 (CLI provisioning + reconnect)
• (Meshcore): runtime companion transport switching (BLE <-> WiFi/TCP) with persisted WiFi config + UI support #1968 (runtime BLE↔WiFi/TCP transport switching)
• fix(companion): gate private-key export and factory-reset on WiFi builds #2527 (security gating for WiFi builds)

If/when one of those lands, this env benefits uniformly along with all other _companion_radio_wifi envs. Not landing this env now means T3-S3 users have no upstream WiFi path today. Happy to drop the env later if maintainers decide to deprecate the compile-time approach repo-wide.

Listing in the web flasher

This PR only touches the firmware repo. To make the new variant appear in https://flasher.meshcore.io/, a companion PR to meshcore-dev/flasher.meshcore.io is required (adding a companionWifi role + per-board firmware entry to config.json). I'll open that as a follow-up once this lands and the first companion-vX.Y.Z release contains the new binaries — same approach would benefit the other 16 WiFi envs listed above.