refactor(domains): share target resolution and CDP error mapping

The ref-vs-x/y branch turned out to exist in one tool, not four; it is now
one helper with tests covering the half-specified-coordinate and stale-ref
cases. cdpCall folds the repeated cdp_error mapping at 24 active-session
call sites; target-scoped callOnTarget/callBrowser sites are left alone.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/src/domains/target.ts b/src/domains/target.ts
new file mode 100644
index 0000000..8a9ee07
--- /dev/null
+++ b/src/domains/target.ts
@@ -0,0 +1,35 @@
+import type { BrowserClient } from "../client";
+import { type Result, err, ok } from "../util/result";
+import type { ToolErr } from "../util/tool";
+import { resolveRefToBox } from "./ref-resolve";
+
+export type PointArgs = {
+  readonly ref?: string | undefined;
+  readonly x?: number | undefined;
+  readonly y?: number | undefined;
+};
+
+export type ResolvedTarget = {
+  readonly x: number;
+  readonly y: number;
+  readonly label: string;
+};
+
+export const resolveTarget = async (
+  client: BrowserClient,
+  args: PointArgs,
+): Promise<Result<ResolvedTarget, ToolErr>> => {
+  if (args.ref !== undefined) {
+    const box = await resolveRefToBox(client, args.ref);
+    if (!box.success) return box;
+    return ok({
+      x: box.data.cx,
+      y: box.data.cy,
+      label: `[${args.ref}] (${box.data.cx}, ${box.data.cy})`,
+    });
+  }
+  if (args.x !== undefined && args.y !== undefined) {
+    return ok({ x: args.x, y: args.y, label: `(${args.x}, ${args.y})` });
+  }
+  return err({ kind: "invalid_state", message: "Provide either `ref` or both `x` and `y`." });
+};