#9984: feat: Add Discord embed support to message action schema

## What Adds `embeds` field to the message action schema for Discord sends. ## Why The Discord plugin already **fully supports embeds** in the send action: - `src/channels/plugins/actions/discord/handle-action.ts` extracts `params.embeds` - `src/discord/send.shared.ts` passes embeds directly to Discord's REST API This capability just wasn't exposed in the tool schema, so agents couldn't discover or use it. ## How Simple schema addition using the same flexible pattern as Adaptive Cards: - Array of objects with `additionalProperties: true` - Allows full access to all Discord embed features without rigid validation ## Example Usage ```json { "action": "send", "target": "#general", "message": "Check this out!", "embeds": [{ "title": "Hello World", "description": "This is a rich embed", "color": 5814783, "fields": [ { "name": "Field 1", "value": "Value 1", "inline": true } ], "footer": { "text": "OpenClaw" } }] } ## Testing Has been tested fully with Discord. <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> This PR updates the message tool’s TypeBox schema (`src/agents/tools/message-tool.ts`) to expose a new optional `embeds` field on the send action parameters. The new field is defined as an array of free-form objects (`additionalProperties: true`), mirroring the existing flexible pattern used for `card`, so agents can discover and supply Discord embed payloads that are already supported downstream by the Discord message action implementation. <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with minimal risk. - Only a single schema file changes, adding an optional field using an existing permissive schema pattern (similar to `card`). No control flow or runtime logic is modified, and the change is backward-compatible because the new parameter is optional. - No files require special attention <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} <!-- /greptile_comment -->