Add the harness, envs, per-bot models and chat attachments

- Harness: providers, model catalog synced hourly, automatic free picks,
  cooldowns, tool loop with context trimming, MCP computer tools
- Bots queue runs replies and tasks through the harness; jobs wait
  (attempt refunded) while every model is resting
- Envs: Settings > Environment, scoped general/workspace/computer,
  written to computers and redacted from tool output
- Models: Settings > Models, per-harness provider select defaulting to
  OpenRouter, and a models modal on each bot's chat (the coordinator's
  edits the defaults)
- Chat: thinking row while a reply runs, file attachments (upload,
  paste, drop) that replies read as images, audio and document text
- Fix media uploads failing after a user's first file, and private
  files being served from the public media path

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/harness/tools/tool-definition.ts

@@ -0,0 +1,24 @@
+import { z } from "zod";
+import type { HarnessTool, HarnessToolDefinition } from "../types";
+
+type Params = {
+    tool: HarnessTool;
+};
+
+/**
+ * What the model sees of a tool: its name, description and arguments as
+ * JSON schema (draft 7, the one providers accept most widely).
+ */
+export default function toolDefinition({ tool }: Params): HarnessToolDefinition {
+    const { $schema, ...parameters } = (
+        tool.schema
+            ? z.toJSONSchema(tool.schema, { target: "draft-7", io: "input" })
+            : tool.parameters || { type: "object", properties: {} }
+    ) as Record<string, unknown>;
+
+    return {
+        name: tool.name,
+        description: tool.description,
+        parameters,
+    };
+}