feat(whatsapp): add configurable media max size

- Add whatsapp.mediaMaxMb config option (default: 50MB)
- Increases default from previous 5MB hardcoded limit
- Allows receiving larger documents/media files
- Per-account override via whatsapp.accounts.*.mediaMaxMb

Fixes #<issue-number> (if applicable)

src/config/types.ts

@@ -131,6 +131,8 @@ export type WhatsAppConfig = {
   groupPolicy?: GroupPolicy;
   /** Outbound text chunk size (chars). Default: 4000. */
   textChunkLimit?: number;
+  /** Maximum media file size in MB. Default: 50. */
+  mediaMaxMb?: number;
   /** Disable block streaming for this account. */
   blockStreaming?: boolean;
   /** Merge streamed block replies before sending. */
@@ -160,6 +162,7 @@ export type WhatsAppAccountConfig = {
   groupAllowFrom?: string[];
   groupPolicy?: GroupPolicy;
   textChunkLimit?: number;
+  mediaMaxMb?: number;
   blockStreaming?: boolean;
   /** Merge streamed block replies before sending. */
   blockStreamingCoalesce?: BlockStreamingCoalesceConfig;

src/config/zod-schema.ts

@@ -1227,6 +1227,7 @@ export const ClawdbotSchema = z.object({
               groupAllowFrom: z.array(z.string()).optional(),
               groupPolicy: GroupPolicySchema.optional().default("open"),
               textChunkLimit: z.number().int().positive().optional(),
+              mediaMaxMb: z.number().int().positive().optional(),
               blockStreaming: z.boolean().optional(),
               blockStreamingCoalesce: BlockStreamingCoalesceSchema.optional(),
               groups: z
@@ -1262,6 +1263,7 @@ export const ClawdbotSchema = z.object({
       groupAllowFrom: z.array(z.string()).optional(),
       groupPolicy: GroupPolicySchema.optional().default("open"),
       textChunkLimit: z.number().int().positive().optional(),
+      mediaMaxMb: z.number().int().positive().optional().default(50),
       blockStreaming: z.boolean().optional(),
       blockStreamingCoalesce: BlockStreamingCoalesceSchema.optional(),
       actions: z

src/web/inbound.ts

@@ -83,6 +83,7 @@ export async function monitorWebInbox(options: {
   accountId: string;
   authDir: string;
   onMessage: (msg: WebInboundMessage) => Promise<void>;
+  mediaMaxMb?: number;
 }) {
   const inboundLogger = getChildLogger({ module: "web-inbound" });
   const inboundConsoleLog = createSubsystemLogger(
@@ -375,9 +376,12 @@ export async function monitorWebInbox(options: {
       try {
         const inboundMedia = await downloadInboundMedia(msg, sock);
         if (inboundMedia) {
+          const maxBytes = (options.mediaMaxMb ?? 50) * 1024 * 1024;
           const saved = await saveMediaBuffer(
             inboundMedia.buffer,
             inboundMedia.mimetype,
+            "inbound",
+            maxBytes,
           );
           mediaPath = saved.path;
           mediaType = inboundMedia.mimetype;