feat(webhooks): configurable agent run timeout (default 600s) (#1267)

Replace the hardcoded 30s webhook agent-run deadline with a configurable
timeout (default 600s, cap 3600s) for both the async worker and the
sync/test HTTP handler. Legitimate multi-step runs were dying at 30s
mid-tool-call; the same request over WebSocket completed fine.

- internal/webhooks/timeout.go: ResolveTimeoutSec helper (<=0 → 600s, cap 3600s)
- WorkerConfig.AsyncAgentTimeout (async worker) + WebhookLLMHandler.syncTimeout
  (sync + admin test), wired from config
- config keys gateway.webhook_{async,sync}_timeout_sec, also settable via
  GOCLAW_WEBHOOK_{ASYNC,SYNC}_TIMEOUT_SEC env (env overrides config)
- tests: timeout bounds + config file/env override

cmd/gateway_http_wiring.go

@@ -16,6 +16,7 @@ import (
 	"github.com/nextlevelbuilder/goclaw/internal/store"
 	"github.com/nextlevelbuilder/goclaw/internal/store/pg"
 	"github.com/nextlevelbuilder/goclaw/internal/tools"
+	"github.com/nextlevelbuilder/goclaw/internal/webhooks"
 )
 
 // httpHandlers bundles the results of wireHTTP() for passing to wireHTTPHandlersOnServer.
@@ -232,6 +233,7 @@ func (d *gatewayDeps) wireHTTPHandlersOnServer(
 				d.pgStores.Webhooks,
 				sharedWebhookLimiter, // K10: shared limiter
 				nil,                  // lane: nil → internal default (4-slot); configurable in future via cfg
+				webhooks.ResolveTimeoutSec(d.cfg.Gateway.WebhookSyncTimeoutSec),
 			)
 			llmH.SetEncKey(webhookEncKey) // K6: decrypt secret at HMAC verify time
 			d.server.SetWebhookLLMHandler(llmH)

cmd/gateway_lifecycle.go

@@ -172,6 +172,7 @@ func (d *gatewayDeps) runLifecycle(
 			webhooks.WorkerConfig{
 				WorkerConcurrency:    workerConcurrency,
 				PerTenantConcurrency: 4,
+				AsyncAgentTimeout:    webhooks.ResolveTimeoutSec(d.cfg.Gateway.WebhookAsyncTimeoutSec),
 			},
 		)
 		// K6: decrypt raw secret for outbound HMAC signing using the same key as inbound verify.