[omartelo]

What

The page answer an agent gets from its session's browser (browser_info, browser_click, browser_press) now names the console errors the page showed since the agent's last page answer, once each:

url: http://127.0.0.1:5173/
title: Console
console error: load failed: 42
console error: Failed to load resource: the server responded with a status of 404 (Not Found) http://127.0.0.1:5173/missing.png
console error: Uncaught TypeError: Cannot read properties of null (reading 'f') (http://127.0.0.1:5173/:3)
text: throw
...

An agent that changed a web app and drives it had only a screenshot to hint that the page threw; now the exception or the failed load is in the answer.

How

• internal/browser/console.go: the page hands each console error to a per-session sink, kept until the next page answer, the same pattern as downloads. Sources, all already enabled by chromedp: Runtime.consoleAPICalled of type error, Runtime.exceptionThrown (first line of the error plus url:line), and Log.entryAdded at level error (a resource that failed to load, CSP). Warnings, info and log messages are not collected.
• Caps are named constants: the first consoleErrorMax (5) errors are kept, the rest only counted and reported as (N more console errors); each text is folded to one line and cut to consoleTextMax (200) runes. A page that throws in a loop costs a bounded number of tokens.
• Page.Listen takes one more callback; api.BrowserPageInfo gains consoleErrors and consoleErrorsMore (contract.golden updated).
• The browser_info/click/press tool descriptions say so in one clause; docs/browser-tab.md has a Console errors section; CHANGELOG entry under Added.

Privacy

The text is exactly what the page logs (its own console.error arguments, an exception's message, the URL of a resource that failed). lich reads nothing else from the page for it; a page that logs a form's value hands it to the agent, as it would to anyone with DevTools open.

Language

Like the rest of the page answer, the console error: lines are English outside the prompt-language catalogs. Moving the page answer into the catalogs is a separate follow-up.

Test plan

• Unit tests with the fake page: reported once by read, click and press; cap and count; one-line cut; text of a console call, an exception and a log entry.
• Live test (console_live_test.go, same skip rule as the other Chrome tests): a page that logs an error and a warning and asks for a missing image; the first reads name the error and the 404, not the warning; a click on a button that throws answers with the one Uncaught TypeError; the next read repeats nothing. 30/30 runs green.
• The two existing Listen calls in chrome_live_test.go get the new argument (the signature changed), nothing else.
• gofmt, go vet ./... and go test ./... green, rebased on feat(browser): browser_info waits for text to appear or go #955 and fix(browser): stage Chrome's downloads in the session profile #960.