cli+lsp: refactor main packages into internal runners; add tests

- Move CLI logic to internal/hexaicli with Run/RunWithClient
- Move LSP logic to internal/hexailsp with Run/RunWithFactory
- Extract helpers; keep behavior identical for both binaries
- Add unit tests for hexaicli (input parsing, messages, streaming) and
  hexailsp (factory wiring, client creation, logging settings)
- Add top-of-file summaries and 'Not yet reviewed by a human' comments to all Go files
- Update README with internal package docs

1 files changed, 63 insertions, 0 deletions

diff --git a/internal/hexaicli/testhelpers_test.go b/internal/hexaicli/testhelpers_test.go
new file mode 100644
index 0000000..4a25ff1
--- /dev/null
+++ b/internal/hexaicli/testhelpers_test.go
@@ -0,0 +1,63 @@
+// Summary: Test helpers for Hexai CLI tests (stdin swapping and fake LLM clients/streamers).
+// Not yet reviewed by a human
+package hexaicli
+
+import (
+    "context"
+    "os"
+    "path/filepath"
+    "testing"
+
+    "hexai/internal/llm"
+)
+
+// setStdin sets os.Stdin from a string and returns a restore func and reader.
+func setStdin(t *testing.T, content string) (func(), *os.File) {
+    t.Helper()
+    tmpDir := t.TempDir()
+    fpath := filepath.Join(tmpDir, "stdin.txt")
+    if err := os.WriteFile(fpath, []byte(content), 0o600); err != nil {
+        t.Fatalf("write temp stdin: %v", err)
+    }
+    f, err := os.Open(fpath)
+    if err != nil {
+        t.Fatalf("open temp stdin: %v", err)
+    }
+    old := os.Stdin
+    os.Stdin = f
+    restore := func() {
+        f.Close()
+        os.Stdin = old
+    }
+    return restore, f
+}
+
+// fakeClient implements llm.Client for tests.
+type fakeClient struct {
+    name    string
+    model   string
+    resp    string
+    gotMsgs []llm.Message
+}
+
+func (f *fakeClient) Chat(ctx context.Context, messages []llm.Message, opts ...llm.RequestOption) (string, error) {
+    f.gotMsgs = append([]llm.Message{}, messages...)
+    return f.resp, nil
+}
+func (f fakeClient) Name() string        { return f.name }
+func (f fakeClient) DefaultModel() string { return f.model }
+
+// fakeStreamer implements llm.Streamer over fakeClient.
+type fakeStreamer struct {
+    fakeClient
+    chunks []string
+    sMsgs  []llm.Message
+}
+
+func (s *fakeStreamer) ChatStream(ctx context.Context, messages []llm.Message, onDelta func(string), opts ...llm.RequestOption) error {
+    s.sMsgs = append([]llm.Message{}, messages...)
+    for _, c := range s.chunks {
+        onDelta(c)
+    }
+    return nil
+}