feat(hooks): add agentId support to webhook mappings (#13672)

* feat(hooks): add agentId support to webhook mappings

Allow webhook mappings to route hook runs to a specific agent via
the new `agentId` field. This enables lightweight agents with minimal
bootstrap files to handle webhooks, reducing token cost per hook run.

The agentId is threaded through:
- HookMappingConfig (config type + zod schema)
- HookMappingResolved + HookAction (mapping types)
- normalizeHookMapping + buildActionFromMapping (mapping logic)
- mergeAction (transform override support)
- HookAgentPayload + normalizeAgentPayload (direct /hooks/agent endpoint)
- dispatchAgentHook → CronJob.agentId (server dispatch)

The existing runCronIsolatedAgentTurn already supports agentId on
CronJob — this change simply wires it through from webhook mappings.

Usage in config:
  hooks.mappings[].agentId = "my-agent"

Usage via POST /hooks/agent:
  { "message": "...", "agentId": "my-agent" }

Includes tests for mapping passthrough and payload normalization.
Includes doc updates for webhook.md.

* fix(hooks): enforce webhook agent routing policy + docs/changelog updates (#13672) (thanks @BillChirico)

* fix(hooks): harden explicit agent allowlist semantics (#13672) (thanks @BillChirico)

---------

Co-authored-by: Pip <pip@openclaw.ai>
Co-authored-by: Gustavo Madeira Santana <gumadeiras@gmail.com>

src/config/zod-schema.hooks.ts

@@ -12,6 +12,7 @@ export const HookMappingSchema = z
     action: z.union([z.literal("wake"), z.literal("agent")]).optional(),
     wakeMode: z.union([z.literal("now"), z.literal("next-heartbeat")]).optional(),
     name: z.string().optional(),
+    agentId: z.string().optional(),
     sessionKey: z.string().optional(),
     messageTemplate: z.string().optional(),
     textTemplate: z.string().optional(),