feat: import agents_and_robots platform as unibots (Matrix-out, unibus transport)

Reemplaza el scaffold del echobot por la plataforma completa de bots traida
desde ~/DataProyects/Github/agents_and_robots tras la operacion Matrix-out:
los bots ya no hablan por Matrix sino por el bus unibus (modelo todo-rooms +
E2E via shell/transportunibus sobre github.com/enmanuel/unibus/pkg/client).

- go.mod: replace de unibus -> ../unibus y de fn-registry -> ../../../.. (paths
  relativos reajustados a la nueva ubicacion dentro de fn_registry).
- app.md: bump a 0.2.0, descripcion + arquitectura + comandos + gotchas reales.
- modulo Go conservado como github.com/enmanuel/agents (sin reescribir imports).

agents_and_robots queda archivado como museo de la era Matrix.

shell/logger/logger_test.go

@@ -0,0 +1,77 @@
+package logger
+
+import (
+	"context"
+	"encoding/json"
+	"log/slog"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestNewAgentLogger_WritesJSONL(t *testing.T) {
+	dir := t.TempDir()
+	l, cleanup, err := NewAgentLogger(LoggerConfig{
+		BaseDir: dir,
+		AgentID: "test-bot",
+		Level:   slog.LevelDebug,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer cleanup()
+
+	l.Info("hello world", FieldAction, "greet", FieldReason, "testing")
+
+	// Force flush by closing.
+	cleanup()
+
+	files, _ := os.ReadDir(filepath.Join(dir, "test-bot"))
+	if len(files) == 0 {
+		t.Fatal("expected at least one log file")
+	}
+
+	data, err := os.ReadFile(filepath.Join(dir, "test-bot", files[0].Name()))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var m map[string]any
+	if err := json.Unmarshal(data, &m); err != nil {
+		t.Fatalf("log line is not valid JSON: %s", data)
+	}
+	if m["msg"] != "hello world" {
+		t.Errorf("msg = %v, want hello world", m["msg"])
+	}
+	if m[FieldAgentID] != "test-bot" {
+		t.Errorf("agent_id = %v, want test-bot", m[FieldAgentID])
+	}
+	if m[FieldAction] != "greet" {
+		t.Errorf("action = %v, want greet", m[FieldAction])
+	}
+}
+
+func TestNewAgentLogger_Stdout(t *testing.T) {
+	l, cleanup, err := NewAgentLogger(LoggerConfig{
+		BaseDir: "stdout",
+		AgentID: "dev-bot",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer cleanup()
+	// Just verify it doesn't panic.
+	l.Info("stdout test")
+}
+
+func TestTraceIDContext(t *testing.T) {
+	ctx := context.Background()
+	if got := TraceIDFromCtx(ctx); got != "" {
+		t.Errorf("empty ctx should return empty trace, got %q", got)
+	}
+
+	ctx = WithTraceID(ctx, "abc-123")
+	if got := TraceIDFromCtx(ctx); got != "abc-123" {
+		t.Errorf("trace = %q, want abc-123", got)
+	}
+}