Add repeater and room server environments for M5Stack Unit C6L

- Rename companion_radio_ble env to follow naming conventions
- Add m5stack_unit_c6l_repeater with packet logging
- Add m5stack_unit_c6l_room_server with packet logging
- All environments use matching LoRa settings (910.525MHz, SF7, BW62.5)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: TheRealHaoLiu

variants/m5stack_unit_c6l/platformio.ini

@@ -37,7 +37,7 @@ build_flags =
 build_src_filter = ${esp32c6_base.build_src_filter}
   +<../variants/m5stack_unit_c6l>
 
-[env:M5Stack_Unit_C6L_companion_radio_ble_]
+[env:m5stack_unit_c6l_companion_radio_ble]
 extends = m5stack_unit_c6l
 build_flags = ${m5stack_unit_c6l.build_flags}
   ; US/Canada recommended preset (narrow mode)
@@ -72,3 +72,44 @@ lib_deps =
   densaugeo/base64 @ ~1.4.0
   end2endzone/NonBlockingRTTTL@^1.3.0
   adafruit/Adafruit SSD1306 @ ^2.5.13
+
+[env:m5stack_unit_c6l_repeater]
+extends = m5stack_unit_c6l
+build_flags = ${m5stack_unit_c6l.build_flags}
+  ; LoRa settings - must match other devices on your mesh
+  -D LORA_FREQ=910.525
+  -D LORA_SF=7
+  -D LORA_BW=62.5
+  -D LORA_CR=5
+  -D ADVERT_NAME='"M5Stack C6L Repeater"'
+  -D ADVERT_LAT=0.0
+  -D ADVERT_LON=0.0
+  -D ADMIN_PASSWORD='"password"'
+  -D MAX_NEIGHBOURS=50
+  -D MESH_PACKET_LOGGING=1
+build_src_filter = ${m5stack_unit_c6l.build_src_filter}
+  -<../variants/m5stack_unit_c6l/UITask.cpp>
+  +<../examples/simple_repeater>
+lib_deps =
+  ${m5stack_unit_c6l.lib_deps}
+  bakercp/CRC32 @ ^2.0.0
+
+[env:m5stack_unit_c6l_room_server]
+extends = m5stack_unit_c6l
+build_flags = ${m5stack_unit_c6l.build_flags}
+  ; LoRa settings - must match other devices on your mesh
+  -D LORA_FREQ=910.525
+  -D LORA_SF=7
+  -D LORA_BW=62.5
+  -D LORA_CR=5
+  -D ADVERT_NAME='"M5Stack C6L Room"'
+  -D ADVERT_LAT=0.0
+  -D ADVERT_LON=0.0
+  -D ADMIN_PASSWORD='"password"'
+  -D ROOM_PASSWORD='"hello"'
+  -D MESH_PACKET_LOGGING=1
+build_src_filter = ${m5stack_unit_c6l.build_src_filter}
+  -<../variants/m5stack_unit_c6l/UITask.cpp>
+  +<../examples/simple_room_server>
+lib_deps =
+  ${m5stack_unit_c6l.lib_deps}