Performs wildcard matching across labor_category, vendor_name, and
idv_piid fields. This is the primary search tool for finding rates.

Returns matching rate records plus aggregation statistics (wage_stats,
percentiles, education breakdown, business size) covering the FULL
result set even when individual hits are capped at 10,000.

Important notes:
- These are NTE (not-to-exceed) ceiling rates, not prices paid
- Rates are fully burdened hourly rates from GSA MAS contracts
- Data refreshes nightly from vendor price proposal tables
- Use P50 from percentiles for median (more accurate than median_price)

Filter parameters:
- education_level: AA, BA, HS, MA, PHD, TEC (pipe-delimited for OR: 'BA|MA')
- experience_min/max: years of experience range
- price_min/max: hourly rate range in USD
- business_size: 'S' (small) or 'O' (other/large)
- security_clearance: 'yes' or 'no'
- sin: Special Item Number (e.g., '54151S' for IT Professional Services)
- worksite: NOT supported (the v3 API silently ignores it; passing a
  value raises so callers are not handed unfiltered data)

ordering: current_price, labor_category, vendor_name, education_level,
min_years_experience, next_year_price, idv_piid, business_size.
sort: 'asc' or 'desc'.

exclude: pipe-delimited hit _id values to exclude from results and stats.