Improve Select Element screenshots with visual context

[sudo-eugene]

Refs #172

What changed

Select Element screenshots now have an optional surrounding-context mode that can capture a nearby container and draw a border-only rounded highlight around the selected element. The default remains the original tight element crop, and teams opt into more context with data-element-context-max-area.

The review screen and docs now point people to that setting, and GitHub issues explain the highlight using the exact resolved color. The local check config also now recognizes the existing semantic-release workflow usage so the pre-PR check suite passes.

Why this shape (and not the obvious alternative)

The useful triage behavior is the larger contextual screenshot, but making that the default would change the existing Select Element behavior for every install and could make captures larger or slower. Keeping the default at the selected element, then letting teams expand context explicitly, preserves the current behavior while still supporting AI-assisted review workflows.

The highlight is a border using the widget accent color instead of an overlay. An overlay can obscure the actual element styling, which is exactly the detail the screenshot is meant to preserve.

This branch is built directly on current main and does not include the full CSS-path metadata work or the private fixture cleanup work from the other open PRs.

Out of scope

This does not add a new selector metadata format. It only improves the visual evidence captured by Select Element screenshots.

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Test plan

• git diff --check passed.
• npm run format:check passed.
• make check passed. ESLint still reports the existing file-size warnings for src/widget/capture-flow.ts and src/widget/screenshot.ts; the critical audit gate passed with moderate-only audit output.
• NODE_OPTIONS=--no-experimental-webstorage make test passed: 13 files, 236 tests. Plain make test hit this machine's experimental Node localStorage behavior before the rerun.
• make build-all passed.
• CI=true make test-e2e-shard SHARD=1/2 passed: 89 tests.
• CI=true make test-e2e-shard SHARD=2/2 passed: 89 tests.
• NODE_OPTIONS=--no-experimental-webstorage npx vitest run test/api.test.ts passed after the final caption wording change.

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[github-actions]

🎉 This PR is included in version 1.36.0 🎉

The release is available on GitHub release

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