refactor: one door from a tool to the browser

Four routes coexisted: cdpCall, a raw client.session().call, a session
held in a local and called directly, and client.evaluateJs — and five
files mixed two or three of them. The CdpError-to-ToolErr mapping was
hand-copied at nine sites, plus a private copy in isolated-tab.ts.

domains/cdp-call.ts now owns all of it: cdpErrToToolErr, cdpCall,
cdpCallOnTarget, cdpCallBrowser, evalJs. Every other file under
src/domains goes through them, which also removes a pile of
`if (!r.success) return err({ kind: "cdp_error", ... })` boilerplate in
favour of returning the failed Result as-is.

Two scanner rules keep it that way, scoped to src/domains/ so the layer
that legitimately owns the session — cdp/ and client.ts — is unaffected.
Scoping is new to the rule model; without it the rules fired on the
transport itself.

One deliberate behaviour change: a CDP timeout now surfaces as
kind "timeout" rather than "cdp_error". isolated-tab.ts already did this
and the other 13 sites flattened it; the shared mapper uses the honest
label rather than preserving the mislabel.

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

1 files changed, 3 insertions, 2 deletions

diff --git a/src/domains/js.ts b/src/domains/js.ts
index a64b4ac..b43387c 100644
--- a/src/domains/js.ts
+++ b/src/domains/js.ts
@@ -7,6 +7,7 @@ import { Markdown, Text } from "@mariozechner/pi-tui";
 import { getMarkdownTheme, keyHint } from "@mariozechner/pi-coding-agent";
 import { type Result, err, ok } from "../util/result";
 import { defineBrowserTool, type ToolErr, type ToolOk } from "../util/tool";
+import { evalJs } from "./cdp-call";
 import { applyTruncation } from "../util/truncate";
 import { asNumber, asRecord, asString, isRecord } from "../util/guards";
 
@@ -47,8 +48,8 @@ export const executeJsTool = defineBrowserTool({
   parameters: ExecuteJsArgs,
   concurrency: "parallel",
   async handler(args, { client }): Promise<Result<ToolOk, ToolErr>> {
-    const r = await client.evaluateJs(args.expression, args.targetId);
-    if (!r.success) return err({ kind: "cdp_error", message: r.error.message });
+    const r = await evalJs(client, args.expression, args.targetId);
+    if (!r.success) return r;
     const valueStr = r.data === undefined ? "undefined" : JSON.stringify(r.data);
     const truncated = await applyTruncation(valueStr, "js");
     let pretty: string | undefined;