Add ProfileConfig struct and profiles map to Config, allowing named
mode presets in config.toml (e.g. [profiles.dev] modes = ["app","cmd"]).
Remove the --providers/-p CLI flag and repurpose -p as the short form
for --prompt. Add --profile flag that loads modes from a named profile.
Mode resolution priority: --mode > --profile > config defaults.
vikingowl
6391711df2