feat(linkedin): add job search adapter

[SiweiMa]

Summary

• src/clis/linkedin/search.ts — New adapter to search LinkedIn jobs via Voyager job cards.

Usage

# Basic search
opencli linkedin search --query 'software engineer' --location 'San Francisco Bay Area' -f json

# Search with filters
opencli linkedin search   --query 'software engineer'   --location 'San Francisco Bay Area'   --company 'OpenAI'   --experience_level entry   --job_type full-time   --date_posted week   --remote remote   --limit 3   -f json

# Include full job description + apply URL (slower)
opencli linkedin search   --query 'software engineer'   --location 'San Francisco Bay Area'   --limit 1   --details   -f json

Search arguments

Param	Default	Description
--query	required	Job search keywords
--location	none	LinkedIn location text
--limit	10	Number of jobs to return (max 100)
--start	0	Result offset for pagination
--company	none	Comma-separated company names or LinkedIn company IDs
--experience_level	none	internship, entry, associate, mid-senior, director, executive
--job_type	none	full-time, part-time, contract, temporary, volunteer, internship, other
--date_posted	none	any, month, week, 24h
--remote	none	on-site, hybrid, remote
--details	false	Include full job description and apply URL

Output

Default output columns:

• rank
• title
• company
• location
• listed
• salary
• url

With --details, each item also includes:

• description
• apply_url

Notes

• Uses Strategy.HEADER with authenticated browser requests against LinkedIn Voyager.
• Company names are resolved from the live LinkedIn filter UI before calling the API.
• --details opens each returned job page to expand the "About the job" section and extract the full description + apply URL, so it is intentionally opt-in.

Test plan

• npm run build
• opencli linkedin search --query 'software engineer' --location 'San Francisco Bay Area' --limit 1 -f json
• opencli linkedin search --query 'software engineer' --location 'San Francisco Bay Area' --company 'OpenAI' --limit 2 -f json
• opencli linkedin search --query 'software engineer' --location 'San Francisco Bay Area' --experience_level entry --job_type full-time --date_posted week --limit 2 -f json
• opencli linkedin search --query 'software engineer' --location 'San Francisco Bay Area' --limit 1 --details -f json