- Switch API reload to `NewRootedDiskFilesystem(Root: ".")` for cwd-relative ops
- Use `NewString` for RTMP.App/FFmpeg.Binary (drop absolute/exec enforcement)
- Remove absolute path resolution in JSON config store
- Improve `diskFilesystem.LookPath`: use `filepath.IsAbs`, add Windows `.exe` suffix
- Simplify FFmpeg skills init error handling
Allows portable execution from any dir (e.g., containers), fixes Windows compat.
The progress and probe parser had both their own prelude parsing implementation
in case the json variant is not available. Now there's a new package for this
implementation that both use.
If a program has an ID (in case of srt+mpegts) then this was no recognized by the
parser and these inputs/outputs were not detected.
