#7157: docs(browser): recommend openclaw managed profile as default

This updates the docs to recommend using the *managed + isolated* openclaw browser profile as the default for stability. - Suggests setting browser.defaultProfile: "openclaw" for day-to-day agent browsing/automation. - Clarifies that chrome is the *extension relay* profile and requires attaching a tab via the OpenClaw Browser Relay toolbar icon (badge ON). - Keeps the relay flow as an explicit choice when you want to drive your existing browser session. No runtime / behavior changes — documentation only. <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> This PR updates browser-related documentation to recommend using the OpenClaw-managed `openclaw` browser profile as the default (`browser.defaultProfile: "openclaw"`) for day-to-day automation, and clarifies that the `chrome` profile is specifically for the Browser Relay extension flow (requires manually attaching a tab via the extension toolbar icon/badge). Changes are limited to docs (`docs/gateway/configuration.md`, `docs/tools/browser.md`, `docs/tools/index.md`) and align the configuration snippet and tool reference notes around the new recommended default. <h3>Confidence Score: 5/5</h3> - This PR is safe to merge; it is documentation-only and internally consistent. - Reviewed all diffs in the three modified docs files and checked for consistency with other docs references to `browser.defaultProfile` and the Browser Relay attachment flow. No broken internal links, misleading defaults, or conflicting guidance introduced. - No files require special attention <!-- greptile_other_comments_section --> _{(4/5) You can add custom instructions or style guidelines for the agent [here](https://app.greptile.com/review/github)!} **Context used:** - Context from `dashboard` - CLAUDE.md ([source](https://app.greptile.com/review/custom-context?memory=fd949e91-5c3a-4ab5-90a1-cbe184fd6ce8)) - Context from `dashboard` - AGENTS.md ([source](https://app.greptile.com/review/custom-context?memory=0d0c8278-ef8e-4d6c-ab21-f5527e322f13)) <!-- /greptile_comment -->