feat: renderizar Markdown a HTML en mensajes Matrix con goldmark

Se reemplaza SendText por SendMarkdown en todos los puntos donde el agente
envía respuestas: runtime.go (comandos built-in y tareas orquestadas),
effects/runner.go (acciones Reply) y tools/matrix.go (matrix_send tool).

shell/matrix/client.go ahora usa goldmark para convertir Markdown a HTML real
en el campo FormattedBody del evento Matrix, cumpliendo con la spec de Matrix
para mensajes formateados. El Body conserva el markdown raw como fallback.

Se añade dependencia github.com/yuin/goldmark v1.7.16.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

agents/runtime.go

@@ -391,7 +391,7 @@ func (a *Agent) handleTaskEvent(ctx context.Context, msg bus.AgentMessage) {
 	}
 
 	// Send reply to Matrix room
-	if sendErr := a.matrix.SendText(ctx, roomID, reply); sendErr != nil {
+	if sendErr := a.matrix.SendMarkdown(ctx, roomID, reply); sendErr != nil {
 		a.logger.Error("failed to send orchestrated reply to Matrix", "err", sendErr)
 	}
 
@@ -453,13 +453,13 @@ func (a *Agent) handleEvent(ctx context.Context, msgCtx decision.MessageContext,
 		if handler, ok := a.commands[cmdName]; ok {
 			a.logger.Info("command_executed", "command", cmdName)
 			reply := handler(ctx, msgCtx)
-			_ = a.matrix.SendText(ctx, roomID, reply)
+			_ = a.matrix.SendMarkdown(ctx, roomID, reply)
 			return
 		}
 
 		// Unknown command — never falls through to rules or LLM
 		a.logger.Info("command_unknown", "command", msgCtx.Command)
-		_ = a.matrix.SendText(ctx, roomID,
+		_ = a.matrix.SendMarkdown(ctx, roomID,
 			fmt.Sprintf("Comando desconocido: !%s. Usa !help para ver comandos disponibles.", msgCtx.Command))
 		return
 	}

go.mod

@@ -51,6 +51,7 @@ require (
 	github.com/wk8/go-ordered-map/v2 v2.1.8 // indirect
 	github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e // indirect
 	github.com/yosida95/uritemplate/v3 v3.0.2 // indirect
+	github.com/yuin/goldmark v1.7.16 // indirect
 	go.mau.fi/util v0.8.1 // indirect
 	golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546 // indirect
 	golang.org/x/net v0.30.0 // indirect

go.sum

@@ -110,6 +110,8 @@ github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e h1:JVG44RsyaB9T2KIHavM
 github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e/go.mod h1:RbqR21r5mrJuqunuUZ/Dhy/avygyECGrLceyNeo4LiM=
 github.com/yosida95/uritemplate/v3 v3.0.2 h1:Ed3Oyj9yrmi9087+NczuL5BwkIc4wvTb5zIM+UJPGz4=
 github.com/yosida95/uritemplate/v3 v3.0.2/go.mod h1:ILOh0sOhIJR3+L/8afwt/kE++YT040gmv5BQTMR2HP4=
+github.com/yuin/goldmark v1.7.16 h1:n+CJdUxaFMiDUNnWC3dMWCIQJSkxH4uz3ZwQBkAlVNE=
+github.com/yuin/goldmark v1.7.16/go.mod h1:ip/1k0VRfGynBgxOz0yCqHrbZXhcjxyuS66Brc7iBKg=
 go.mau.fi/util v0.8.1 h1:Ga43cz6esQBYqcjZ/onRoVnYWoUwjWbsxVeJg2jOTSo=
 go.mau.fi/util v0.8.1/go.mod h1:T1u/rD2rzidVrBLyaUdPpZiJdP/rsyi+aTzn0D+Q6wc=
 golang.org/x/crypto v0.31.0 h1:ihbySMvVjLAeSH1IbfcRTkD/iNscyz8rGzjF/E5hV6U=

shell/effects/runner.go

@@ -22,6 +22,7 @@ type Result struct {
 // MatrixSender is satisfied by shell/matrix.Client.
 type MatrixSender interface {
 	SendText(ctx context.Context, roomID, text string) error
+	SendMarkdown(ctx context.Context, roomID, markdown string) error
 	SendTyping(ctx context.Context, roomID string, typing bool) error
 }
 
@@ -65,7 +66,7 @@ func (r *Runner) executeOne(ctx context.Context, roomID string, a decision.Actio
 		if a.Reply.ThreadID != "" {
 			target = a.Reply.ThreadID
 		}
-		err := r.matrix.SendText(ctx, target, a.Reply.Content)
+		err := r.matrix.SendMarkdown(ctx, target, a.Reply.Content)
 		return Result{Action: a, Output: a.Reply.Content, Err: err}
 
 	case decision.ActionKindSSH:

shell/matrix/client.go

@@ -3,6 +3,7 @@ package matrix
 
 import (
 	"context"
+	"bytes"
 	"crypto/sha256"
 	"encoding/hex"
 	"fmt"
@@ -12,6 +13,7 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/yuin/goldmark"
 	"maunium.net/go/mautrix"
 	"maunium.net/go/mautrix/crypto"
 	"maunium.net/go/mautrix/crypto/cryptohelper"
@@ -269,17 +271,29 @@ func (c *Client) SendText(ctx context.Context, roomID, text string) error {
 }
 
 // SendMarkdown sends a formatted (Markdown) message to a room.
+// Body contains the raw markdown (plaintext fallback per Matrix spec).
+// FormattedBody contains the HTML rendered by goldmark.
 func (c *Client) SendMarkdown(ctx context.Context, roomID, markdown string) error {
+	html := mdToHTML(markdown)
 	content := event.MessageEventContent{
 		MsgType:       event.MsgText,
 		Body:          markdown,
 		Format:        event.FormatHTML,
-		FormattedBody: markdown, // mautrix can render markdown -> HTML if needed
+		FormattedBody: html,
 	}
 	_, err := c.raw.SendMessageEvent(ctx, id.RoomID(roomID), event.EventMessage, content)
 	return err
 }
 
+// mdToHTML converts a Markdown string to HTML using goldmark.
+func mdToHTML(md string) string {
+	var buf bytes.Buffer
+	if err := goldmark.Convert([]byte(md), &buf); err != nil {
+		return md // fallback to raw markdown on error
+	}
+	return buf.String()
+}
+
 // SendReaction sends a reaction to an event.
 func (c *Client) SendReaction(ctx context.Context, roomID, eventID, reaction string) error {
 	_, err := c.raw.SendReaction(ctx, id.RoomID(roomID), id.EventID(eventID), reaction)

tools/matrix.go

@@ -9,6 +9,7 @@ import (
 // Satisfied by shell/matrix.Client.
 type MatrixSender interface {
 	SendText(ctx context.Context, roomID, text string) error
+	SendMarkdown(ctx context.Context, roomID, markdown string) error
 }
 
 // NewMatrixSend creates a matrix_send tool that sends a message to a Matrix room.
@@ -29,7 +30,7 @@ func NewMatrixSend(sender MatrixSender) Tool {
 				return Result{Err: fmt.Errorf("matrix_send: room_id and message are required")}
 			}
 
-			if err := sender.SendText(ctx, roomID, message); err != nil {
+			if err := sender.SendMarkdown(ctx, roomID, message); err != nil {
 				return Result{Err: fmt.Errorf("matrix_send: %w", err)}
 			}