WEBDEV-9424: Migrate search-service into elements

[jbuckner]

Moves search-service into src/services/search-service/, ported from @internetarchive/search-service 2.7.2 (the published source). All 209 tests came over, converted from mocha and sinon to vitest. It imports the local item-metadata and result-type. Changes from a straight port:

• The four enums (SearchType, AggregationSortType, FilterConstraint, SearchServiceErrorType) are const objects with a same-named type, with the same values, because the repo forbids enums.
• subject on the hit classes is typed StringListField. Against item-metadata 1.5.0 the old StringField type no longer compiles (type only, no runtime change).
• The entry point is index.ts since search-service.ts is the class.

Stacked on #171 (item-metadata). The branch also carries #156 (result-type) until it merges.

🤖 Generated with Claude Code

https://claude.ai/code/session_01CjuFdHEwY7MowcqkUxxudu

[github-actions]

PR Preview Action v1.8.1
🚀 View preview at https://internetarchive.github.io/elements/pr/pr-172/
Built to branch ghpages at 2026-10-09 01:23 UTC. Preview will be ready when the GitHub Pages deployment is complete.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 92.97125% with 44 lines in your changes missing coverage. Please review.
✅ Project coverage is 92.00%. Comparing base (db7d0df) to head (374c06a).

Files with missing lines	Patch %	Lines
...arch-service/search-backend/base-search-backend.ts	87.50%	7 Missing and 5 partials ⚠️
...rch-service/mock-response-generator.test-helper.ts	52.94%	8 Missing ⚠️
...earch-service/responses/search-response-details.ts	89.33%	0 Missing and 8 partials ⚠️
...search-service/models/hit-types/web-archive-hit.ts	44.44%	2 Missing and 3 partials ⚠️
...h-service/models/hit-types/favorited-search-hit.ts	42.85%	3 Missing and 1 partial ⚠️
...vices/search-service/search-param-url-generator.ts	92.85%	0 Missing and 4 partials ⚠️
.../services/search-service/models/search-metadata.ts	92.85%	1 Missing and 1 partial ⚠️
src/services/search-service/filter-map-builder.ts	97.77%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@                      Coverage Diff                      @@
##           WEBDEV-9419-item-metadata     #172      +/-   ##
=============================================================
+ Coverage                      91.73%   92.00%   +0.27%     
=============================================================
  Files                            126      152      +26     
  Lines                           4075     4701     +626     
  Branches                         858     1026     +168     
=============================================================
+ Hits                            3738     4325     +587     
- Misses                           147      163      +16     
- Partials                         190      213      +23     

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[jbuckner]

Second commit is a security fix beyond the port. FilterMapBuilder.addFilter('__proto__', 'x', ...) wrote to Object.prototype (same in the published 2.7.2). It now ignores __proto__, constructor and prototype keys, with tests. Worth fixing upstream and checking where collection-browser feeds user input into addFilter.

[jbuckner]

Updated the FilterMapBuilder fix to match iaux-search-service#103 (WEBDEV-9479): only __proto__ is ignored and lookups use own-property checks, so values like "prototype" still work. Same tests as #103.

[bfalling]

NOTE: Sure wish we could get rid of that /beta part of the path...

[bfalling]

LGTM