test: expand env-var-path coverage

[karthiknadig]

Adds 7 new unit tests to pet-env-var-path (from 4 to 11 total).

New coverage:

• Empty search locations, all-Windows-Apps filtering
• is_windows_apps_path: home-based matching, subdirectory matching, unrelated path rejection
• normalize_search_path: non-existent and existing paths

Fixes #389

[github-actions]

Performance Report (Linux) ➖

Metric	PR (P50)	PR (P95)	Baseline (P50)	Delta	Change
Server Startup	1ms	1ms	0ms	1ms	N/A%
Full Refresh	65ms	122ms	53ms	12ms	20.0%

Results based on 10 iterations. P50 = median, P95 = 95th percentile.

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Legend

• 🚀 Significant speedup (>100ms faster)
• ✅ Faster than baseline
• ➖ No significant change
• 🔺 Slower than baseline (>100ms)
• ⚠️ Significant slowdown (>500ms)

[github-actions]

Performance Report (macOS)

Metric	PR (P50)	PR (P95)	Baseline (P50)	Delta
Server Startup	62ms	493ms	107ms	-45ms
Full Refresh	125ms	27050ms	198ms	-73ms

Results based on 10 iterations. P50 = median, P95 = 95th percentile.

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Legend

• 🚀 Significant speedup (>100ms faster)
• ✅ Faster than baseline
• ➖ No significant change
• 🔺 Slower than baseline (>100ms)
• ⚠️ Significant slowdown (>500ms)

[github-actions]

Test Coverage Report (Linux)

Metric	Value
Current Coverage	75.7%
Base Branch Coverage	75.6%
Delta	.1% ✅

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Coverage increased! Great work!

[github-actions]

Test Coverage Report (Windows)

Metric	Value
Current Coverage	72.62%
Base Branch Coverage	72.49%
Delta	0.13% ✅

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Coverage increased! Great work!

[github-actions]

Performance Report (Windows) ✅

Metric	PR (P50)	PR (P95)	Baseline (P50)	Delta	Change
Server Startup	12ms	15ms	11ms	1ms	9.1%
Full Refresh	199ms	4598ms	202ms	-3ms	-1.5%

Results based on 10 iterations. P50 = median, P95 = 95th percentile.

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Legend

• 🚀 Significant speedup (>100ms faster)
• ✅ Faster than baseline
• ➖ No significant change
• 🔺 Slower than baseline (>100ms)
• ⚠️ Significant slowdown (>500ms)