roam v0.3.0 — roam version

Adds a version command, and fixes what its absence was hiding.

$ roam version
{"ok":true,"tool":"roam","version":"0.3.0","providers":["anthropic","openai","debri"]}

--version and -v work too. A binary you scp onto a machine you may not own has to be able to say what it is — without this the only way to check a deployed roam was to run strings on it.

Which is how this slipped: roam_version() still returned 0.2.0 after v0.2.1 shipped, so every telemetry ping under-reported the binary and nothing noticed. make release now refuses to build when the Makefile's VERSION and the constant in telemetry.src disagree, verified in both directions.

curl -fsSL https://github.com/javimosch/roam/releases/latest/download/roam-x86_64-linux -o roam
chmod +x roam && ./roam version