Use XDG Base Directory

[schoedon]

Codex hardcodes default paths to live in /home/runner.

Available sub-commands:

codex-v0.1 persistence prover [OPTIONS]...

The following options are available:

 -cd, --circuit-dir          Directory where Codex will store proof circuit data
                            [=/home/runner/.cache/codex/circuits].
     --circom-r1cs          The r1cs file for the storage circuit
                            [=/home/runner/.cache/codex/circuits/proof_main.r1cs].
     --circom-wasm          The wasm file for the storage circuit
                            [=/home/runner/.cache/codex/circuits/proof_main.wasm].
     --circom-zkey          The zkey file for the storage circuit
                            [=/home/runner/.cache/codex/circuits/proof_main.zkey].
     --circom-no-zkey       Ignore the zkey file - use only for testing! [=false].
     --proof-samples        Number of samples to prove [=5].
     --max-slot-depth       The maximum depth of the slot tree [=32].
     --max-dataset-depth    The maximum depth of the dataset tree [=8].
     --max-block-depth      The maximum depth of the network block merkle tree [=5].
     --max-cell-elements    The maximum number of elements in a cell [=67].

Implement XDG Base Directory structure, specifically:

• XDG_DATA_HOME
• XDG_CONFIG_HOME
• XDG_CACHE_HOME

https://specifications.freedesktop.org/basedir-spec/latest/