Add ctx.ui.theme getter for styling status text with theme colors

- Add theme property to HookUIContext interface
- Implement in interactive, RPC, and no-op contexts
- Add status-line.ts example hook
- Document styling with theme colors in hooks.md

packages/coding-agent/src/core/custom-tools/loader.ts

@@ -14,6 +14,7 @@ import * as path from "node:path";
 import { fileURLToPath } from "node:url";
 import { createJiti } from "jiti";
 import { getAgentDir, isBunBinary } from "../../config.js";
+import { theme } from "../../modes/interactive/theme/theme.js";
 import type { ExecOptions } from "../exec.js";
 import { execCommand } from "../exec.js";
 import type { HookUIContext } from "../hooks/types.js";
@@ -94,6 +95,9 @@ function createNoOpUIContext(): HookUIContext {
 		custom: async () => undefined as never,
 		setEditorText: () => {},
 		getEditorText: () => "",
+		get theme() {
+			return theme;
+		},
 	};
 }