Canonical values for agent config filters

Resolves free text to the exact strings an agent config accepts, so a create body never fails on a near-miss spelling. region feeds regions and authorLocation; industry feeds industries; title feeds currentTitle, pastTitle and authorTitle; school is available for completeness. There is no country vocabulary: region returns LinkedIn geographies that include sub-national areas such as "California, United States", so it is NOT a source for companyCountries or leadCompanyCountries — those take full English country names only ("United States", "Germany") and no lookup endpoint serves them. Returns at most 10 values, best match first; an empty array means nothing matched — try a broader term. Counts against the agents bucket (30/min) and, upstream, a separate lookup bucket (120/min).

Errors:

• 400 INVALID_REQUEST — The agents service rejected the request for a reason this API does not model specifically. The request is not retryable unchanged.
• 422 VALIDATION_FAILED — The request failed this endpoint's own validation — param names the offending field and message says why.
• 429 RATE_LIMITED — The agents bucket is exhausted: 30 requests per minute or 2,000 per day per token owner, shared by every /business/agents operation (a 429 raised by the agents service is relayed with this code too). Retry after the Retry-After header.
• 500 UNEXPECTED_ERROR — The agents service failed (5xx, refused service credential, or a timeout after 60s) or the rate limiter was unavailable. Retry later; quote request_id to support.

Requires one of the following token scopes: agents.