WIP: Save agent roles integration work before CHORUS rebrand

- Agent roles and coordination features
- Chat API integration testing
- New configuration and workspace management

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

vendor/github.com/libp2p/go-flow-metrics/meter.go

@@ -0,0 +1,71 @@
+package flow
+
+import (
+	"fmt"
+	"sync/atomic"
+	"time"
+)
+
+// Snapshot is a rate/total snapshot.
+type Snapshot struct {
+	Rate       float64
+	Total      uint64
+	LastUpdate time.Time
+}
+
+// NewMeter returns a new Meter with the correct idle time.
+//
+// While zero-value Meters can be used, their "last update" time will start at
+// the program start instead of when the meter was created.
+func NewMeter() *Meter {
+	return &Meter{
+		snapshot: Snapshot{
+			LastUpdate: time.Now(),
+		},
+	}
+}
+
+func (s Snapshot) String() string {
+	return fmt.Sprintf("%d (%f/s)", s.Total, s.Rate)
+}
+
+// Meter is a meter for monitoring a flow.
+type Meter struct {
+	accumulator uint64
+
+	// managed by the sweeper loop.
+	registered bool
+
+	// Take lock.
+	snapshot Snapshot
+}
+
+// Mark updates the total.
+func (m *Meter) Mark(count uint64) {
+	if count > 0 && atomic.AddUint64(&m.accumulator, count) == count {
+		// The accumulator is 0 so we probably need to register. We may
+		// already _be_ registered however, if we are, the registration
+		// loop will notice that `m.registered` is set and ignore us.
+		globalSweeper.Register(m)
+	}
+}
+
+// Snapshot gets a snapshot of the total and rate.
+func (m *Meter) Snapshot() Snapshot {
+	globalSweeper.snapshotMu.RLock()
+	defer globalSweeper.snapshotMu.RUnlock()
+	return m.snapshot
+}
+
+// Reset sets accumulator, total and rate to zero.
+func (m *Meter) Reset() {
+	globalSweeper.snapshotMu.Lock()
+	atomic.StoreUint64(&m.accumulator, 0)
+	m.snapshot.Rate = 0
+	m.snapshot.Total = 0
+	globalSweeper.snapshotMu.Unlock()
+}
+
+func (m *Meter) String() string {
+	return m.Snapshot().String()
+}