docs(readme): add a README — the repo had none

A stranger landing here saw an empty page. One sentence on what it is, the
install line, the first call, and a pointer at LLM.md for the depth.

README.md

@@ -0,0 +1,47 @@
+# Hanzo Research (Go)
+
+The Go client for `/v1/research`: record an experiment as a falsifiable test — hypothesis,
+attempts, verdict — and query the evidence back.
+
+Stdlib only (`net/http` + `encoding/json`), no external modules, so any service can import
+it without dragging in a dependency graph.
+
+## Install
+
+```bash
+go get github.com/hanzoai/research
+```
+
+## Use it
+
+```go
+c := research.New(research.Config{Project: "enso-bench"})
+
+exp, _ := c.Experiment(kind, subject, task)
+exp.Record(item, model, research.Result{ /* one attempt */ })
+exp.Log("what happened")
+exp.Conclude(research.Proven, because, value)
+```
+
+`Finish(value)` seals a run without an explicit verdict; a hypothesis with no verdict
+records as `Inconclusive`. `Record` is idempotent, so a retried attempt does not double
+count.
+
+Authentication is your per-org API key, read from the environment like every other Hanzo
+client.
+
+## One record, every language
+
+The server keys each experiment on `(project, id = kind:subject:task)`, so the Python,
+Rust and C++ clients upsert the same row this one does. JSON spacing differs between them
+and is immaterial to the store. If you already know one of those clients, the verbs here
+are the same.
+
+## Docs
+
+[`LLM.md`](LLM.md) is the full surface and the semantics of each verb. `example_test.go`
+is a runnable walkthrough.
+
+## License
+
+See [LICENSE](LICENSE).