fix(tests): resolve failing LLM proxy and thesaurus persistence tests

[AlexMikhalev]

Summary

This PR fixes the main failing tests identified in the workspace:

✅ LLM Proxy Integration Tests (12/12 passing)

• Add serial execution attributes to prevent environment variable contamination
• Implement proper environment variable cleanup between tests
• Fix ANTHROPIC_AUTH_TOKEN vs ANTHROPIC_API_KEY precedence handling

✅ Thesaurus Persistence Tests (3/3 passing)

• Add proper KG path resolution for test environments
• Configure KnowledgeGraph settings with correct docs/src/kg paths
• Handle different test execution directories (crates/, workspace root, etc.)

✅ Core Service Fixes

• Remove unused PathBuf import warning in lib.rs
• Fix test path resolution for thesaurus building from KG files
• Ensure consistent test behavior across different execution contexts

Test Results

Before fix:

• ❌ LLM Proxy Integration Tests: Failing due to environment variable contamination
• ❌ Thesaurus Persistence Tests: Failing due to incorrect KG path resolution
• ❌ Compilation errors due to missing imports

After fix:

• ✅ LLM Proxy Integration Tests: 12/12 passing
• ✅ Thesaurus Persistence Tests: 3/3 passing
• ✅ terraphim_service library tests: 112/112 passing
• ✅ Build: Successful
• ✅ Clippy: No warnings for modified code

Changes Made

1. LLM Proxy Test Fixes (crates/terraphim_service/tests/llm_proxy_integration_test.rs)

#[tokio::test]
#[serial]  // Added to all test functions
async fn test_llm_proxy_auto_configuration() {
    // Tests now run sequentially to prevent env var contamination
}

2. Thesaurus Path Resolution (crates/terraphim_service/tests/thesaurus_persistence_test.rs)

// Added proper KG path resolution
let project_root = std::env::current_dir().unwrap_or_else(|_| PathBuf::from("."));
let kg_path = if project_root.ends_with("crates") {
    project_root.join("../docs/src/kg")
} else {
    project_root.join("docs/src/kg")
};

3. Core Service Test Fix (crates/terraphim_service/src/lib.rs)

• Fixed PathBuf import usage
• Added KG path configuration for test environments

4. Desktop Test Fix (desktop/src-tauri/tests/thesaurus_prewarm_test.rs)

• Applied same KG path resolution pattern

Test Plan

• LLM Proxy Integration Tests: cargo test -p terraphim_service --test llm_proxy_integration_test -- --test-threads=1
• Thesaurus Persistence Tests: cargo test -p terraphim_service --test thesaurus_persistence_test -- --test-threads=1
• Core Service Library Tests: cargo test -p terraphim_service --lib
• Build Validation: cargo build --workspace --release
• Code Quality: cargo clippy -p terraphim_service --all-targets --all-features -- -D warnings

All tests now pass and maintain proper isolation when run together.

🤖 Generated with Claude Code

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[chatgpt-codex-connector]

Fix MCP integration test command pattern

When MCP integration tests exist, the runner always fails them because it invokes cargo test -p terraphim_server --test '*' -- mcp, but Cargo doesn’t accept wildcard names for --test and requires the concrete integration test target. This command errors out before executing any tests, so the script will report integration tests as failed even when they would otherwise pass.

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