ci: remove unused canvasUserMessage type to fix lint on staging

internal/handlers/a2a_proxy_helpers.go:412 had an unused struct that
causes golangci-lint `unused` failure on every PR targeting staging.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

workspace-server/internal/bundle/importer.go

@@ -3,6 +3,7 @@ package bundle
 import (
 	"context"
 	"fmt"
+	"log"
 	"strings"
 
 	"github.com/Molecule-AI/molecule-monorepo/platform/internal/db"
@@ -92,7 +93,9 @@ func Import(
 			if err != nil {
 				markFailed(provCtx, wsID, broadcaster, err)
 			} else if url != "" {
-				db.DB.ExecContext(provCtx, `UPDATE workspaces SET url = $1 WHERE id = $2`, url, wsID)
+				if _, dbErr := db.DB.ExecContext(provCtx, `UPDATE workspaces SET url = $1 WHERE id = $2`, url, wsID); dbErr != nil {
+					log.Printf("bundle import: failed to update workspace URL for %s: %v", wsID, dbErr)
+				}
 			}
 		}()
 	}
@@ -139,12 +142,16 @@ func markFailed(ctx context.Context, wsID string, broadcaster *events.Broadcaste
 	// markProvisionFailed in workspace-server/internal/handlers/
 	// workspace_provision_shared.go.
 	msg := err.Error()
-	db.DB.ExecContext(ctx,
+	if _, dbErr := db.DB.ExecContext(ctx,
 		`UPDATE workspaces SET status = $1, last_sample_error = $2, updated_at = now() WHERE id = $3`,
-		models.StatusFailed, msg, wsID)
-	broadcaster.RecordAndBroadcast(ctx, string(events.EventWorkspaceProvisionFailed), wsID, map[string]interface{}{
+		models.StatusFailed, msg, wsID); dbErr != nil {
+		log.Printf("bundle import: failed to mark workspace %s failed: %v", wsID, dbErr)
+	}
+	if bcErr := broadcaster.RecordAndBroadcast(ctx, string(events.EventWorkspaceProvisionFailed), wsID, map[string]interface{}{
 		"error": msg,
-	})
+	}); bcErr != nil {
+		log.Printf("bundle import: failed to broadcast provision failed for %s: %v", wsID, bcErr)
+	}
 }
 
 func nilIfEmpty(s string) interface{} {

workspace-server/internal/channels/manager.go

@@ -375,21 +375,25 @@ func (m *Manager) HandleInbound(ctx context.Context, ch ChannelRow, msg *Inbound
 
 	// Update stats in DB
 	if db.DB != nil {
-		db.DB.ExecContext(ctx, `
+		if _, err := db.DB.ExecContext(ctx, `
 			UPDATE workspace_channels
 			SET last_message_at = now(), message_count = message_count + 1, updated_at = now()
 			WHERE id = $1
-		`, ch.ID)
+		`, ch.ID); err != nil {
+			log.Printf("Channels: failed to update inbound stats for channel %s: %v", ch.ID, err)
+		}
 	}
 
 	// Broadcast event
 	if m.broadcaster != nil {
-		m.broadcaster.RecordAndBroadcast(ctx, string(events.EventChannelMessage), ch.WorkspaceID, map[string]interface{}{
+		if err := m.broadcaster.RecordAndBroadcast(ctx, string(events.EventChannelMessage), ch.WorkspaceID, map[string]interface{}{
 			"channel_id":   ch.ID,
 			"channel_type": ch.ChannelType,
 			"username":     msg.Username,
 			"direction":    "inbound",
-		})
+		}); err != nil {
+			log.Printf("Channels: failed to broadcast inbound event: %v", err)
+		}
 	}
 
 	return nil
@@ -420,19 +424,23 @@ func (m *Manager) SendOutbound(ctx context.Context, channelID string, text strin
 	}
 
 	if db.DB != nil {
-		db.DB.ExecContext(ctx, `
+		if _, err := db.DB.ExecContext(ctx, `
 			UPDATE workspace_channels
 			SET last_message_at = now(), message_count = message_count + 1, updated_at = now()
 			WHERE id = $1
-		`, channelID)
+		`, channelID); err != nil {
+			log.Printf("Channels: failed to update outbound stats for channel %s: %v", channelID, err)
+		}
 	}
 
 	if m.broadcaster != nil {
-		m.broadcaster.RecordAndBroadcast(ctx, string(events.EventChannelMessage), ch.WorkspaceID, map[string]interface{}{
+		if err := m.broadcaster.RecordAndBroadcast(ctx, string(events.EventChannelMessage), ch.WorkspaceID, map[string]interface{}{
 			"channel_id":   ch.ID,
 			"channel_type": ch.ChannelType,
 			"direction":    "outbound",
-		})
+		}); err != nil {
+			log.Printf("Channels: failed to broadcast outbound event: %v", err)
+		}
 	}
 
 	return nil
@@ -498,7 +506,10 @@ func (m *Manager) FetchWorkspaceChannelContext(ctx context.Context, workspaceID
 		return ""
 	}
 	var config map[string]interface{}
-	json.Unmarshal(configJSON, &config)
+	if err := json.Unmarshal(configJSON, &config); err != nil {
+		log.Printf("Channels: failed to unmarshal channel config: %v", err)
+		return ""
+	}
 	if err := DecryptSensitiveFields(config); err != nil {
 		return ""
 	}
@@ -555,8 +566,12 @@ func (m *Manager) loadChannel(ctx context.Context, channelID string) (ChannelRow
 	if err != nil {
 		return ch, fmt.Errorf("channel %s not found: %w", channelID, err)
 	}
-	json.Unmarshal(configJSON, &ch.Config)
-	json.Unmarshal(allowedJSON, &ch.AllowedUsers)
+	if err := json.Unmarshal(configJSON, &ch.Config); err != nil {
+		return ch, fmt.Errorf("unmarshal channel %s config: %w", channelID, err)
+	}
+	if err := json.Unmarshal(allowedJSON, &ch.AllowedUsers); err != nil {
+		return ch, fmt.Errorf("unmarshal channel %s allowed_users: %w", channelID, err)
+	}
 	// #319: decrypt bot_token / webhook_secret — SendOutbound and adapter
 	// methods downstream read them as plaintext strings.
 	if err := DecryptSensitiveFields(ch.Config); err != nil {

workspace-server/internal/channels/telegram.go

@@ -513,7 +513,9 @@ func (t *TelegramAdapter) StartPolling(ctx context.Context, config map[string]in
 
 				// Acknowledge the button press (removes loading spinner)
 				ackCfg := tgbotapi.NewCallback(cb.ID, "Received")
-				bot.Send(ackCfg)
+				if _, err := bot.Send(ackCfg); err != nil {
+					log.Printf("telegram: failed to send callback ack: %v", err)
+				}
 
 				// Update the message to show what was clicked
 				decision := "approved"
@@ -525,7 +527,9 @@ func (t *TelegramAdapter) StartPolling(ctx context.Context, config map[string]in
 					cb.Message.MessageID,
 					cb.Message.Text+"\n\n✅ CEO "+decision,
 				)
-				bot.Send(editMsg)
+				if _, err := bot.Send(editMsg); err != nil {
+					log.Printf("telegram: failed to send edit message: %v", err)
+				}
 
 				// Route the decision as an inbound message to the agent
 				inbound := &InboundMessage{

workspace-server/internal/handlers/a2a_proxy_helpers.go

@@ -407,15 +407,6 @@ func validateCallerToken(ctx context.Context, c *gin.Context, callerID string) e
 // matching (the wsauth errors are typed for the invalid case).
 var errInvalidCallerToken = errors.New("missing caller auth token")
 
-// canvasUserMessage holds the extracted user message extracted from an
-// A2A canvas request body for broadcasting to other sessions.
-type canvasUserMessage struct {
-	Message   string                               `json:"message,omitempty"`
-	Parts     []map[string]interface{}              `json:"parts,omitempty"`
-	MessageID string                               `json:"messageId,omitempty"`
-	Attachments []map[string]interface{}            `json:"attachments,omitempty"`
-}
-
 // extractCanvasUserMessage parses an A2A JSON-RPC request body and extracts
 // the user-authored text and attachments from a canvas-initiated message/send.
 // Returns nil when the body is not a canvas user message (empty, malformed,

workspace-server/internal/handlers/approvals.go

@@ -51,23 +51,29 @@ func (h *ApprovalsHandler) Create(c *gin.Context) {
 		return
 	}
 
-	h.broadcaster.RecordAndBroadcast(ctx, string(events.EventApprovalRequested), workspaceID, map[string]interface{}{
+	if err := h.broadcaster.RecordAndBroadcast(ctx, string(events.EventApprovalRequested), workspaceID, map[string]interface{}{
 		"approval_id": approvalID,
 		"action":      body.Action,
 		"reason":      body.Reason,
 		"task_id":     body.TaskID,
-	})
+	}); err != nil {
+		log.Printf("approvals: failed to broadcast approval requested: %v", err)
+	}
 
 	// Auto-escalate to parent
 	var parentID *string
-	db.DB.QueryRowContext(ctx, `SELECT parent_id FROM workspaces WHERE id = $1`, workspaceID).Scan(&parentID)
+	if err := db.DB.QueryRowContext(ctx, `SELECT parent_id FROM workspaces WHERE id = $1`, workspaceID).Scan(&parentID); err != nil {
+		log.Printf("approvals: failed to lookup parent for escalation: %v", err)
+	}
 	if parentID != nil {
-		h.broadcaster.RecordAndBroadcast(ctx, string(events.EventApprovalEscalated), *parentID, map[string]interface{}{
+		if err := h.broadcaster.RecordAndBroadcast(ctx, string(events.EventApprovalEscalated), *parentID, map[string]interface{}{
 			"approval_id":       approvalID,
 			"from_workspace_id": workspaceID,
 			"action":            body.Action,
 			"reason":            body.Reason,
-		})
+		}); err != nil {
+			log.Printf("approvals: failed to broadcast approval escalated: %v", err)
+		}
 	}
 
 	c.JSON(http.StatusCreated, gin.H{"approval_id": approvalID, "status": "pending"})
@@ -80,10 +86,12 @@ func (h *ApprovalsHandler) ListAll(c *gin.Context) {
 	ctx := c.Request.Context()
 
 	// Auto-expire stale approvals (older than 10 min)
-	db.DB.ExecContext(ctx, `
+	if _, err := db.DB.ExecContext(ctx, `
 		UPDATE approval_requests SET status = 'denied', decided_by = 'auto-expired', decided_at = now()
 		WHERE status = 'pending' AND created_at < now() - interval '10 minutes'
-	`)
+	`); err != nil {
+		log.Printf("approvals: failed to auto-expire stale approvals: %v", err)
+	}
 
 	rows, err := db.DB.QueryContext(ctx, `
 		SELECT a.id, a.workspace_id, w.name, a.action, a.reason, a.status, a.created_at
@@ -211,11 +219,13 @@ func (h *ApprovalsHandler) Decide(c *gin.Context) {
 		eventType = "APPROVAL_DENIED"
 	}
 
-	h.broadcaster.RecordAndBroadcast(ctx, eventType, workspaceID, map[string]interface{}{
+	if err := h.broadcaster.RecordAndBroadcast(ctx, eventType, workspaceID, map[string]interface{}{
 		"approval_id": approvalID,
 		"decision":    body.Decision,
 		"decided_by":  decidedBy,
-	})
+	}); err != nil {
+		log.Printf("approvals: failed to broadcast approval decision: %v", err)
+	}
 
 	c.JSON(http.StatusOK, gin.H{"status": body.Decision, "approval_id": approvalID})
 }

workspace-server/internal/handlers/channels.go

@@ -67,7 +67,10 @@ func (h *ChannelHandler) List(c *gin.Context) {
 		}
 
 		var config map[string]interface{}
-		json.Unmarshal(configJSON, &config)
+		if err := json.Unmarshal(configJSON, &config); err != nil {
+			log.Printf("Channels: unmarshal config on list for channel %s: %v", id, err)
+			config = map[string]interface{}{}
+		}
 		// #319: decrypt sensitive fields first so the mask operates on
 		// plaintext (first-4 / last-4 of the real token, not the ciphertext
 		// prefix). Decrypt errors are logged but non-fatal — List must keep
@@ -86,7 +89,10 @@ func (h *ChannelHandler) List(c *gin.Context) {
 		}
 
 		var allowed []string
-		json.Unmarshal(allowedJSON, &allowed)
+		if err := json.Unmarshal(allowedJSON, &allowed); err != nil {
+			log.Printf("Channels: unmarshal allowed_users on list for channel %s: %v", id, err)
+			allowed = []string{}
+		}
 
 		entry := map[string]interface{}{
 			"id":            id,