Fix advanced search for spaced external IDs and clarify v1 FundRef paths

[jrhoads]

Purpose

Fix ror-community/ror-roadmap#71 so unquoted ISNI (and other space-containing) values work in query.advanced, and improve the error for legacy v1 FundRef-style paths from ror-community/ror-roadmap#70 without adding field aliases.

Approach

query.advanced builds an Elasticsearch query_string with default_operator: and. Unquoted whitespace splits the value into multiple terms, so a keyword like 0000 0001 2375 2908 never matches external_ids.all. Quoting already worked; we now auto-quote those values in Python before the query is built.

Roadmap #70’s original Fundref template misspelling is gone under schema v2 (external_ids is an array of {type, all, preferred}). Old paths like external_ids.FundRef.all remain illegal; the validator now explains the v2 fields to use instead.

Key Modifications

• rorapi/common/queries.py: quote_spaced_external_id_values() for external_ids.all / external_ids.preferred; apply it in build_search_query after NFC normalization. Clearer illegal-field message when the path looks like external_ids.<Type>.(all|preferred).
• Unit tests for quoting and the legacy-path hint; integration tests for unquoted ISNI, v2 FundRef syntax, and the legacy error hint.

Important Technical Details

• Only external_ids.all and external_ids.preferred are auto-quoted (values stop at AND/OR/NOT, ), or end of string). Already-quoted values and values without whitespace are unchanged.
• We do not strip spaces or accept unspaced ISNIs (0000000123752908); those are not indexed.
• No legacy aliases for external_ids.FundRef.all — correct v2 forms are external_ids.all:100000908 or external_ids.type:fundref AND external_ids.all:100000908.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Reviewer, please remember our guidelines:

• Be humble in the language and feedback you give, ask don't tell.
• Consider using positive language as opposed to neutral when offering feedback. This is to avoid the negative bias that can occur with neutral language appearing negative.
• Offer suggestions on how to improve code e.g. simplification or expanding clarity.
• Ensure you give reasons for the changes you are proposing.

Test plan

• CI (test-pr / test and flow-guard pass; ruff soft-fails repo-wide with continue-on-error, unrelated)
• Unit tests for quoting helper, advanced-query quoting, and legacy FundRef path hint
• Integration: unquoted external_ids.all:0000 0001 2375 2908 returns https://ror.org/019496w77 (same as quoted); v2 FundRef query returns https://ror.org/02g8xhs57; legacy external_ids.FundRef.all error includes the v2 hint