fix(fetcher): split users field with @-aware parser (#112)

[F88]

Summary

Fixes the users field fragmentation described in #112. The ProtoPedia users
field joins usernames (displayName@profileId) with |, and a | inside a
display name is not escaped, so the plain pipe splitter split one user into
several (real data: prototype id 3571 nisshi.dev | にっし@nishida24|...).

What changed

• New splitPipeSeparatedUsers (lib/fetcher/utils/string-parsers.ts): a
  left-to-right scan that decides, per |, whether it is a username delimiter —
  a | is a delimiter only after an @ has appeared in the current username
  (every username is displayName@profileId, so it always contains @). A |
  seen before the first @ is a display-name character, kept intact.
  • No trimming — each username is the exact substring; whitespace is part of
    the display name (ProtoPedia itself renders leading spaces, e.g.
    <h1> とりさん</h1>).
  • Total / non-destructive — never throws, never drops characters.
  • The delimiter decision is localized to one point, so a future upstream
    escaping scheme would only change that decision.
• normalizePrototype uses it for users only; tags / materials /
  events / awards keep the plain splitPipeSeparatedString (they have no @
  anchor — see Data investigation: un-escaped "|" in splitPipeSeparatedString fields (events/tags/materials/awards; users → #112) #120).
• Tests: exhaustive coverage of splitPipeSeparatedUsers (normal / multi-@ /
  empty display / whitespace-preserving / issue-Bug: normalizePrototype fragments users whose display name contains "|" (naive pipe split) #112 re-merge / constraint-
  violating inputs), plus an explicit check that normalizePrototype delegates to
  the @-aware splitter (not the plain one). Existing users fixtures/helpers
  updated to realistic displayName@profileId values.

Scope / limits (see #112 comment for the full spec)

• Fixes (Case A): display name contains | but no @ → re-joined into one
  username. This is the actual bug.
• Out of scope (axis-2): extracting displayName / profileId from a username
  (the @ split, incl. the degenerate @@._.@) → tracked in
  username decoder: parse "displayName@profileId" (last-@ split) promidas-utils#42.
• Inherently unrecoverable (0 in real data): a display name containing both
  @ and | (Case B); a | inside a profileId. The upstream encoding is lossy.

Verification

• npm test — 1366 passed
• npm run typecheck — clean
• npm run lint — clean

Closes #112

🤖 Generated with Claude Code

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Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ All tests successful. No failed tests found.

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[gemini-code-assist]

Code Review

This pull request introduces a specialized parser, splitPipeSeparatedUsers, to correctly handle the users field where display names may contain unescaped pipe (|) characters. Unlike the generic pipe splitter, this new parser is @-aware, ensuring that usernames formatted as displayName@profileId are kept intact even if they contain internal pipes, and it preserves whitespace verbatim. The normalizePrototype utility has been updated to use this new parser, and extensive test suites have been added and updated to reflect the new behavior with realistic test data. There are no review comments, so I have no feedback to provide.

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[Copilot]

Pull request overview

This PR fixes incorrect fragmentation of ProtoPedia users values when a maker’s display name contains an unescaped ASCII | by introducing an @-aware splitter and switching normalizePrototype to use it for users only.

Changes:

• Added splitPipeSeparatedUsers to parse the upstream users string without splitting | characters that occur before the first @ in a username.
• Updated normalizePrototype to use the new users splitter while leaving other pipe-separated fields on the existing trimmed splitter.
• Updated/expanded tests and fixtures to use realistic displayName@profileId inputs and to assert delegation to the new splitter.

Reviewed changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
lib/fetcher/utils/string-parsers.ts	Adds splitPipeSeparatedUsers implementing an @-aware scan to avoid users fragmentation.
lib/fetcher/utils/normalize-prototype.ts	Switches users normalization to use splitPipeSeparatedUsers and updates doc examples.
lib/fetcher/utils/index.ts	Re-exports splitPipeSeparatedUsers alongside existing utilities.
lib/fetcher/tests/utils/string-parsers.test.ts	Adds comprehensive unit coverage for splitPipeSeparatedUsers.
lib/fetcher/tests/utils/normalize-prototype/fields.test.ts	Updates users expectations and verifies normalizePrototype delegates to the new splitter.
lib/fetcher/tests/utils/normalize-prototype/type-safety.test.ts	Updates fixtures to displayName@profileId format for users.
lib/fetcher/tests/utils/normalize-prototype/transformation.test.ts	Updates fixtures to displayName@profileId format for users.
lib/fetcher/tests/utils/normalize-prototype/helpers.ts	Updates default upstream fixture users to displayName@profileId format.
lib/fetcher/tests/utils/normalize-prototype/error-handling.test.ts	Adjusts a generic pipe-splitting test to use tags (since users now uses a different splitter).
lib/utils/validation/tests/normalized-prototype.test.ts	Updates validation fixture users string to realistic displayName@profileId format.
lib/repository/validation/tests/serializable-snapshot.test.ts	Updates fixture users string to realistic displayName@profileId format.
lib/repository/tests/protopedia-in-memory-repository/unit/public/snapshot-serialization.test.ts	Updates snapshot serialization fixtures/expectations for users values.
lib/repository/tests/protopedia-in-memory-repository/test-helpers.ts	Updates repository test helper fixture users string to include @.
lib/repository/tests/protopedia-in-memory-repository/perf/data-access.perf.test.ts	Updates perf test fixture users string to include @.
lib/repository/tests/protopedia-in-memory-repository/integration/scenarios.test.ts	Updates integration fixture users string to include @.
lib/store/tests/store.test.ts	Updates store test fixtures to include @ in users entries.
lib/store/tests/store.perf.test.ts	Updates store perf test fixture to include @ in users entries.

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