Add Claude Code stream-json client, report gate, and terminal driver

internal/report/gate.go

@@ -0,0 +1,96 @@
+package report
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"sync"
+
+	"g.fc.run/misc/byre/internal/mcp"
+)
+
+const maxNudges = 3
+
+const nudge = "You must call the report tool (mcp__byre__report) before ending your turn."
+
+type Report struct {
+	Done          []string `json:"done"`
+	OpenQuestions []string `json:"open_questions"`
+	NextSteps     []string `json:"next_steps"`
+	Risks         []string `json:"risks"`
+	Deviations    []string `json:"deviations"`
+}
+
+type Gate struct {
+	OnReport func(Report)
+
+	mu       sync.Mutex
+	reported bool
+	nudges   int
+}
+
+func (g *Gate) Reset() {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	g.reported = false
+	g.nudges = 0
+}
+
+func (g *Gate) Nudges() int {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	return g.nudges
+}
+
+func (g *Gate) Tool() mcp.Tool {
+	return mcp.Tool{
+		Name:        "report",
+		Description: "Report what you did this turn. You must call this before ending every turn. List every departure from the plan in deviations.",
+		InputSchema: json.RawMessage(`{
+			"type": "object",
+			"properties": {
+				"done": {"type": "array", "items": {"type": "string"}},
+				"open_questions": {"type": "array", "items": {"type": "string"}},
+				"next_steps": {"type": "array", "items": {"type": "string"}},
+				"risks": {"type": "array", "items": {"type": "string"}},
+				"deviations": {"type": "array", "items": {"type": "string"}}
+			},
+			"required": ["done"]
+		}`),
+		Handler: g.handle,
+	}
+}
+
+func (g *Gate) handle(ctx context.Context, args json.RawMessage) (string, error) {
+	r := Report{}
+	err := json.Unmarshal(args, &r)
+	if err != nil {
+		return "", fmt.Errorf("malformed report: %w", err)
+	}
+
+	if len(r.Done) == 0 {
+		return "", fmt.Errorf("report must list at least one item in done")
+	}
+
+	g.mu.Lock()
+	g.reported = true
+	g.mu.Unlock()
+
+	if g.OnReport != nil {
+		g.OnReport(r)
+	}
+
+	return "report filed", nil
+}
+
+func (g *Gate) StopHook(ctx context.Context, input json.RawMessage) (map[string]any, error) {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+
+	if g.reported || g.nudges >= maxNudges {
+		return map[string]any{}, nil
+	}
+
+	g.nudges++
+	return map[string]any{"decision": "block", "reason": nudge}, nil
+}