Unable to start due to panic

**Describe the bug**
A clear and concise description of what the bug is.
Unable to start any version of the app

**Expected behavior**
A clear and concise description of what you expected to happen.
App runs

**You have a solution?**
What to do to fix the issue.
No

**UAD log**
Upload the logfile generated by UAD.
RUST_BACKTRACE=full ./uad_gui-linux
thread '' panicked at 'Invalid config file: `missing field `theme` at line 1 column 1`', src/core/config.rs:35:60
stack backtrace:
0: 0x55a60734b54e -
1: 0x55a60716dcfc -
2: 0x55a60731ec64 -
3: 0x55a60734c461 -
4: 0x55a60734d380 -
5: 0x55a60734cf42 -
6: 0x55a60734ceb6 -
7: 0x55a60734cea0 -
8: 0x55a60716b6e2 -
9: 0x55a6073f8a6a -
10: 0x55a607120123 -
11: 0x55a60714303b -
12: 0x55a60763665d -
13: 0x7fc04e2442e4 - __libc_start_main_alias_1
14: 0x55a60711f8ee -
15: 0x0 -
fatal runtime error: failed to initiate panic, error 5
[1] 553597 IOT instruction (core dumped) RUST_BACKTRACE=full ./uad_gui-linux

The panic occurs in src/core/config.rs at line 35 due to a missing 'theme' field in the config file. Start by examining the config file format and the config.rs file to understand the expected structure. Look for where the config file is read and how default values are handled. The fix likely involves ensuring the config file includes a 'theme' field or providing a sensible default when it's missing.

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