Nightly AppImage: symbol library path not set correctly
# Description
The default settings for the nightly app image specify the wrong location for the symbol library. This leads to the symbol library being empty by default.
* The default path is: `/usr/share/kicad/template/sym-lib-table`
* The default path should be: `${KICAD10_SYMBOL_DIR}/../template/sym-lib-table` (or something else relative to the kicad installation).
# Steps to reproduce
1. Run nightly appimage "for the first time", and don't import settings from prior kicad installation.
2. Create new project.
3. Open schematic.
4. Attempt to add "GND" or some other default symbol.
# KiCad Version
```
Application: KiCad Schematic Editor x86_64 on x86_64
Version: 10.0.0-rc1.1-43-ge73caa3b2c, release build
Libraries:
wxWidgets 3.3.2
FreeType 2.13.3
HarfBuzz 6.0.0
FontConfig 2.14.1
libcurl/8.14.1 GnuTLS/3.8.9 zlib/1.3.1 brotli/1.1.0 zstd/1.5.7 libidn2/2.3.8 libpsl/0.21.2 libssh2/1.11.1 nghttp2/1.64.0 librtmp/2.3 OpenLDAP/2.6.10
Platform: Ubuntu 25.10, 64 bit, Little endian, wxGTK, Wayland, ubuntu, wayland, AppImage
Build Info:
Date: Feb 14 2026 06:29:43
wxWidgets: 3.3.2 (wchar_t,STL containers) GTK+ 3.24
Boost: 1.74.0
OCC: 7.9.1
Curl: 7.88.1
ngspice: 45.2
Compiler: GCC 12.2.0 with C++ ABI 1017
KICAD_IPC_API=ON
KICAD_USE_PCH=OFF
Locale:
Lang: en_US
Enc: UTF-8
Num: 1,234.5
Encoded кΩ丈: D0BACEA9E4B888 (sys), D0BACEA9E4B888 (utf8)
```
issue