fix(version): splash screen showed 1.17, not the actual 1.17.1 upstream base

release-notes.md's v1.25 section already documents "Updated upstream
base to companion-v1.17.1", and that merge (68527e7b) is confirmed in
main's history -- but every MESHCORE_VERSION string, including
UITask.cpp's fallback default for boards that don't set it explicitly
(Heltec v3/v4, ThinkNode, Mesh Pocket, T-Echo), was still hardcoded to
the pre-bump "1.17". Bumped every occurrence to "1.17.1" to match what
actually shipped.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

solo/gat562_30s_mesh_kit/platformio.ini

@@ -25,7 +25,7 @@ build_flags =
   -D BLE_PIN_CODE=123456
   -D OFFLINE_QUEUE_SIZE=256
   -D FIRMWARE_SOLO_BUILD=1
-  -D MESHCORE_VERSION='"1.17"'
+  -D MESHCORE_VERSION='"1.17.1"'
   -D UI_SENSORS_PAGE=1
   -D UI_HAS_JOYSTICK_UPDOWN=1
   -D ADVERT_NAME='"@@MAC"'

solo/gat562_mesh_watch13/platformio.ini

@@ -23,7 +23,7 @@ build_flags =
   -D OFFLINE_QUEUE_SIZE=256
   -D DUAL_SERIAL=1
   -D FIRMWARE_SOLO_BUILD=1
-  -D MESHCORE_VERSION='"1.17"'
+  -D MESHCORE_VERSION='"1.17.1"'
   -D UI_SENSORS_PAGE=1
   -D ADVERT_NAME='"@@MAC"'
   ; GPS — re-enable (base undefines it); Serial1 pins 15/16 from variant

solo/lilygo_techo_lite/platformio.ini

@@ -30,7 +30,7 @@ build_flags =
   ; -D MESH_DEBUG=1
   -D ENV_USE_TCA8418=1
   -D FIRMWARE_SOLO_BUILD=1
-  -D MESHCORE_VERSION='"1.17"'
+  -D MESHCORE_VERSION='"1.17.1"'
   -D ENABLE_SCREENSHOT
   -Os
 build_src_filter = ${LilyGo_T-Echo-Lite.build_src_filter}

solo/m5stack_cardputer_adv/platformio.ini

@@ -15,7 +15,7 @@ build_flags =
   -D DUAL_SERIAL=1
   -D OFFLINE_QUEUE_SIZE=256
   -D FIRMWARE_SOLO_BUILD=1
-  -D MESHCORE_VERSION='"1.17"'
+  -D MESHCORE_VERSION='"1.17.1"'
   -D UI_SENSORS_PAGE=1
   ; misc-fixed 6x9 font (full Latin/Greek/Cyrillic), same as the Wio L1/Heltec
   ; solo builds. Solo only: it costs ~14 KB of flash, and this board's own