fix: suppress remaining errcheck warnings for golangci-lint v2

Add explicit error discards (_) for unchecked return values in
HTTP response encoders, resp.Body.Close, json.Unmarshal, and
otel shutdown calls across all non-test files.

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

Author: gcmsg

cmd/peerclawd/main.go

@@ -320,6 +320,6 @@ func main() {
 	if fedService != nil {
 		_ = fedService.Close()
 	}
-	bridgeManager.Close()
+	_ = bridgeManager.Close()
 	logger.Info("PeerClaw gateway stopped")
 }

internal/bridge/a2a/adapter.go

@@ -189,7 +189,7 @@ func (a *Adapter) Handshake(ctx context.Context, card *agentcard.Card) error {
 	if err != nil {
 		return fmt.Errorf("a2a: fetch agent card: %w", err)
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	if resp.StatusCode != http.StatusOK {
 		return fmt.Errorf("a2a: agent card status %d", resp.StatusCode)

internal/bridge/a2a/handler.go

@@ -147,7 +147,7 @@ func (a *Adapter) HandleAgentCard(w http.ResponseWriter, r *http.Request) {
 	}
 
 	w.Header().Set("Content-Type", "application/json")
-	json.NewEncoder(w).Encode(card)
+	_ = json.NewEncoder(w).Encode(card)
 }
 
 // HandleGetTask handles GET /a2a/tasks/{id}.
@@ -165,7 +165,7 @@ func (a *Adapter) HandleGetTask(w http.ResponseWriter, r *http.Request) {
 	}
 
 	w.Header().Set("Content-Type", "application/json")
-	json.NewEncoder(w).Encode(task)
+	_ = json.NewEncoder(w).Encode(task)
 }
 
 // KindNotification is used for checking parsed message kind.
@@ -179,12 +179,12 @@ func writeJSONRPCResult(w http.ResponseWriter, id any, result any) {
 		return
 	}
 	w.Header().Set("Content-Type", "application/json")
-	json.NewEncoder(w).Encode(resp)
+	_ = json.NewEncoder(w).Encode(resp)
 }
 
 func writeJSONRPCError(w http.ResponseWriter, id any, code int, message string) {
 	resp := jsonrpc.NewErrorResponse(id, code, message)
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(http.StatusOK) // JSON-RPC errors still use 200
-	json.NewEncoder(w).Encode(resp)
+	_ = json.NewEncoder(w).Encode(resp)
 }

internal/bridge/acp/adapter.go

@@ -153,7 +153,7 @@ func (a *Adapter) Handshake(ctx context.Context, card *agentcard.Card) error {
 	if err != nil {
 		return fmt.Errorf("acp: fetch manifest: %w", err)
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	if resp.StatusCode != http.StatusOK {
 		return fmt.Errorf("acp: manifest status %d", resp.StatusCode)

internal/bridge/mcp/handler.go

@@ -202,12 +202,12 @@ func writeMCPResult(w http.ResponseWriter, id any, result any) {
 		return
 	}
 	w.Header().Set("Content-Type", "application/json")
-	json.NewEncoder(w).Encode(resp)
+	_ = json.NewEncoder(w).Encode(resp)
 }
 
 func writeMCPError(w http.ResponseWriter, id any, code int, message string) {
 	resp := jsonrpc.NewErrorResponse(id, code, message)
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(http.StatusOK)
-	json.NewEncoder(w).Encode(resp)
+	_ = json.NewEncoder(w).Encode(resp)
 }

internal/observability/otel.go

@@ -73,7 +73,7 @@ func Init(ctx context.Context, cfg config.ObservabilityConfig, logger *slog.Logg
 		otlpmetricgrpc.WithInsecure(),
 	)
 	if err != nil {
-		tp.Shutdown(ctx)
+		_ = tp.Shutdown(ctx)
 		return nil, err
 	}
 

internal/registry/postgres.go

@@ -354,13 +354,13 @@ func (s *PostgresStore) scanCardFromRows(rows *sql.Rows) (*agentcard.Card, error
 }
 
 func (s *PostgresStore) unmarshalCard(card *agentcard.Card, caps, protos, authParams, meta, tags, skills, tools, status, transport string, regAt, hbAt time.Time) {
-	json.Unmarshal([]byte(caps), &card.Capabilities)
-	json.Unmarshal([]byte(protos), &card.Protocols)
-	json.Unmarshal([]byte(authParams), &card.Auth.Params)
-	json.Unmarshal([]byte(meta), &card.Metadata)
-	json.Unmarshal([]byte(tags), &card.PeerClaw.Tags)
-	json.Unmarshal([]byte(skills), &card.Skills)
-	json.Unmarshal([]byte(tools), &card.Tools)
+	_ = json.Unmarshal([]byte(caps), &card.Capabilities)
+	_ = json.Unmarshal([]byte(protos), &card.Protocols)
+	_ = json.Unmarshal([]byte(authParams), &card.Auth.Params)
+	_ = json.Unmarshal([]byte(meta), &card.Metadata)
+	_ = json.Unmarshal([]byte(tags), &card.PeerClaw.Tags)
+	_ = json.Unmarshal([]byte(skills), &card.Skills)
+	_ = json.Unmarshal([]byte(tools), &card.Tools)
 	card.Status = agentcard.AgentStatus(status)
 	card.Endpoint.Transport = protocol.Transport(transport)
 	card.RegisteredAt = regAt

internal/server/dashboard.go

@@ -55,6 +55,6 @@ func DashboardHandler() http.Handler {
 		}
 		w.Header().Set("Content-Type", "text/html; charset=utf-8")
 		w.Header().Set("Cache-Control", "no-cache")
-		w.Write(indexData)
+		_, _ = w.Write(indexData)
 	})
 }

internal/server/http.go

@@ -584,7 +584,7 @@ func (s *HTTPServer) handleFederationDiscover(w http.ResponseWriter, r *http.Req
 func (s *HTTPServer) jsonResponse(w http.ResponseWriter, status int, data any) {
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(status)
-	json.NewEncoder(w).Encode(data)
+	_ = json.NewEncoder(w).Encode(data)
 }
 
 func (s *HTTPServer) jsonError(w http.ResponseWriter, message string, status int) {