[Bug] linkedin profile-read returns empty experience/education/location on v1.8.7

Nobody has claimed this yet.

## Description
`opencli linkedin profile-read --profile-url https://www.linkedin.com/in// -f json` (v1.8.7, macOS, extension v1.0.23, `--window background`) returns `name`, `headline` and `about` correctly, but `location`, `experience`, `education`, `about_character_count`, `about_skills`, `services`, `featured` all come back as empty strings — on profiles that visibly have location, several experience entries and education in the browser.

`opencli linkedin profile-experience --profile-url ` on the same profile returns the 11 experience entries, so the page renders fine; it looks like selector drift in `profile-read`'s section extraction (LinkedIn's profile page changed the section markup recently).

## Repro
1. `opencli doctor` green, logged-in LinkedIn session.
2. `opencli linkedin profile-read --profile-url https://www.linkedin.com/in// -f json`
3. Observe `experience: ""`, `education: ""`, `location: ""` while `headline`/`about` are populated.

## Expected
Sections populated as in `Output columns: profile_url, name, headline, location, about, ..., experience, education, ...`.

## Environment
- opencli 1.8.7 (npm), node 22.22.3 / 26.7.0 (two Macs, same result)
- macOS 25.6, Chrome extension v1.0.23

Start with the `linkedin profile-read` and `linkedin profile-experience` command entry points, then compare how their section extraction handles the current LinkedIn profile markup. Reproduce with the commands in the issue and verify that profile-read populates location, experience, education, and the other listed fields while profile-experience still returns its entries.

Written by the indexing model from the issue text.