fix: partial write error handling

[NguyenHoangSon96]

Closes #

Proposed Changes

• How the errors are handled and test cases adjustment in this PR are heavily influenced by this PR.

Changes

• Tests were modified to accommodate with new definitions of partial write errors, which are:
  - Error response status code is 400.
  - Error response format {"error":"...","data":[{"error_message":"...","line_number":2,"original_line": "..."}]} is returned with data must be an array.
  - accept_partial is set to true.
  - Write endpoint must be api/v3/write_lp.

Checklist

• CHANGELOG.md updated
• Rebased/mergeable
• A test has been added if appropriate
• Tests pass
• Commit messages are conventional
• Sign CLA (if not already signed)

[codecov-commenter]

Codecov Report

❌ Patch coverage is 92.00000% with 12 lines in your changes missing coverage. Please review.
✅ Project coverage is 83.97%. Comparing base (7424b8b) to head (719f8bd).

Files with missing lines	Patch %	Lines
src/client.rs	89.18%	12 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #66      +/-   ##
==========================================
+ Coverage   83.32%   83.97%   +0.65%     
==========================================
  Files          10       10              
  Lines        2027     2141     +114     
==========================================
+ Hits         1689     1798     +109     
- Misses        338      343       +5     

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[Copilot]

Copilot review overview

🟡 Changes recommended

Documentation, error formatting, API compatibility, and skipped or incorrect test assertions remain unresolved.

Get a fresh assessment by requesting another Copilot review.

Review effort: Lite
Findings: 3

Open (3)

• Update README formatting for optional line number · New
• Expect None when original_line is omitted · New
• Remove test filter that skips all new behavior cases · New

What changed in this PR

Updates partial-write error parsing and adds V2/V3 integration coverage.

Changes:

• Adds structured partial-write messages and optional line numbers.
• Expands write-error classification and response parsing.
• Adds mock-server and end-to-end tests.

File	Summary
tests/​write_tests.rs	Adds response classification cases.
tests/​client.rs	Adds V2, V3, and partial-write tests.
src/​error.rs	Updates partial-write error structures.
src/​client.rs	Parses and classifies write errors.

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[Copilot]

Copilot review overview

🟡 Changes recommended

A compile-breaking test issue and a moderate error-display defect remain unresolved.

Get a fresh assessment by requesting another Copilot review.

Review effort: Lite
Findings: 1 · 1 · 1

Open (3)

• Fix multiline string literal syntax · New
• Include the stored message in error display · New
• Assert parsed original lines · New

Resolved since last review (3)

• Remove test filter that skips all new behavior cases
• Expect None when original_line is omitted
• Update README formatting for optional line number

[Copilot]

Copilot review overview

🟡 Changes recommended

A test has a compile error, and several tests can pass without verifying the expected errors.

Get a fresh assessment by requesting another Copilot review.

Review effort: Lite
Findings: 1

Open (1)

• Use correct u16 conversion method in test · New

Resolved since last review (3)

• Fix multiline string literal syntax
• Include the stored message in error display
• Assert parsed original lines

[karel-rehor]

Looks good to me. 🚴 🏁