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/computer/with-computer-env.test.ts

@@ -0,0 +1,48 @@
+import { describe, expect, test } from "bun:test";
+import type { HarnessTool } from "../../types";
+import composeComputerEnvFiles from "./compose-computer-env-files";
+import withComputerEnv from "./with-computer-env";
+
+const echoTool = (name: string): HarnessTool => ({
+    name,
+    description: "",
+    parameters: {},
+    run: async ({ args }) => JSON.stringify(args),
+});
+
+const paths = { shell_path: "/home/gem/.cobble/env", json_path: "/home/gem/.cobble/env.json" };
+const signal = new AbortController().signal;
+
+describe("withComputerEnv", () => {
+    test("sources the env file before bash commands", async () => {
+        const tool = withComputerEnv({ tool: echoTool("sandbox_execute_bash"), ...paths });
+        const sent = JSON.parse(await tool.run({ args: { cmd: "echo $TOKEN" }, signal }));
+
+        expect(sent.cmd).toBe("[ -f /home/gem/.cobble/env ] && . /home/gem/.cobble/env; echo $TOKEN");
+    });
+
+    test("loads the json file before python code", async () => {
+        const tool = withComputerEnv({ tool: echoTool("sandbox_execute_code"), ...paths });
+        const sent = JSON.parse(await tool.run({ args: { code: "print(1)", language: "python" }, signal }));
+
+        expect(sent.code).toStartWith("import json as _cobble_json");
+        expect(sent.code).toEndWith("\nprint(1)");
+    });
+
+    test("leaves other tools alone", () => {
+        const tool = echoTool("browser_navigate");
+        expect(withComputerEnv({ tool, ...paths })).toBe(tool);
+    });
+});
+
+describe("composeComputerEnvFiles", () => {
+    test("escapes single quotes for the shell", () => {
+        expect(
+            composeComputerEnvFiles({ envs: [{ key: "A", value: "it's" }] }).shell,
+        ).toBe(`export A='it'\\''s'\n`);
+    });
+
+    test("is empty without envs", () => {
+        expect(composeComputerEnvFiles({ envs: [] })).toEqual({ shell: "", json: "{}" });
+    });
+});