Query language filter expression for flexible account filtering.

Operators:

• = Exact match
• ~ Substring match (case-insensitive)
• > Greater than
• < Less than
• >= Greater than or equal
• <= Less than or equal
• - Negation
• AND Logical AND
• OR Logical OR

Searchable Fields:

• tin_value, tin_scheme, cin_value, cin_scheme, country, name (from Company)
• name, identifier, created_at, status (from Project/Account)

Examples:

• tin_value=ES92915236C - Find account with specific TIN
• name~"Acme Corp" - Find accounts containing "Acme Corp" in name
• country=es AND tin_scheme=9920 - Spanish accounts with specific TIN scheme
• -status=9 - Exclude archived accounts (status 9)

Returns 400 Bad Request with error code invalid_query if field is not recognized or syntax is invalid.