ERROR: cannot load lexicon file

docker-compose up leads to a successful build and the container is listening on port 80.
But when browsing to port 80: bad gateway.

In the log tscan complains:
```log
tscan-tscan-1 | 11:09:06.40: Ready.
tscan-tscan-1 | 11:09:07.34: Starting wopr 1.43
tscan-tscan-1 | 11:09:07.34: Timbl support built in.
tscan-tscan-1 | 11:09:07.34: Based on timbl 6.9
tscan-tscan-1 | 11:09:07.34: Based on libfolia 2.17
tscan-tscan-1 | 11:09:07.34: ICU support, version 70.1
tscan-tscan-1 | 11:09:07.34: std::numeric_limits::max() = 2147483647
tscan-tscan-1 | 11:09:07.34: std::numeric_limits::max() = 9223372036854775807
tscan-tscan-1 | 11:09:07.34: PID: 2005 PPID: 2004
tscan-tscan-1 | 11:09:07.34: Running: xmlserver
tscan-tscan-1 | 11:09:07.34: xmlserver. Returns a FoLiA document over a sequence.
tscan-tscan-1 | 11:09:07.34: ibasefile: /usr/local/share/tscan/sonar_newspapercorp_tokenized.3.txt.l2r0_-a4+D.ibase
tscan-tscan-1 | 11:09:07.34: port: 7020
tscan-tscan-1 | 11:09:07.34: keep: 1
tscan-tscan-1 | 11:09:07.34: moses: 0
tscan-tscan-1 | 11:09:07.34: lb: 1
tscan-tscan-1 | 11:09:07.34: lc: 2
tscan-tscan-1 | 11:09:07.34: rc: 0
tscan-tscan-1 | 11:09:07.34: verbose: 2
tscan-tscan-1 | 11:09:07.34: timbl:
tscan-tscan-1 | 11:09:07.34: lexicon /usr/local/share/tscan/sonar_newspapercorp_tokenized.3.txt.lex
tscan-tscan-1 | 11:09:07.34: hapax: 0
tscan-tscan-1 | 11:09:07.34: skip_sm: false
tscan-tscan-1 | 11:09:07.34: ERROR: cannot load lexicon file.
tscan-tscan-1 | 11:09:07.34: Result = -1
tscan-tscan-1 | 11:09:07.34: Running for 00s
```

Indeed, there is no lex file in the directory /usr/local/share/tscan/:


Start by inspecting the docker-compose setup and the contents of /usr/local/share/tscan/ in the built container. Trace how the lexicon file is expected to be produced or included, then verify that the service starts without the lexicon error and port 80 responds successfully.

Written by the indexing model from the issue text.