test: add unit tests for pet-windows-store crate (Fixes #389)

[karthiknadig]

Add 9 new unit tests to pet-windows-store (19 total, up from 10):

• Sync from None source clears shared state
• Sync is idempotent
• is_windows_app_folder case insensitivity
• is_windows_app_folder rejects single-char input
• normalize_for_comparison: extended prefix, UNC prefix, plain path
• CachedStoreEnvironment with empty/None symlinks
• try_from returns None on Unix

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	55ms	356ms	53ms	2ms	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]

Test Coverage Report (Linux)

Metric	Value
Current Coverage	75.8%
Base Branch Coverage	75.6%
Delta	.2% ✅

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Coverage increased! Great work!

[github-actions]

Performance Report (macOS)

Metric	PR (P50)	PR (P95)	Baseline (P50)	Delta
Server Startup	46ms	475ms	85ms	-39ms
Full Refresh	92ms	25943ms	175ms	-83ms

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

---

Legend

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

[github-actions]

Performance Report (Windows) ✅

Metric	PR (P50)	PR (P95)	Baseline (P50)	Delta	Change
Server Startup	12ms	13ms	11ms	1ms	9.1%
Full Refresh	184ms	391ms	202ms	-18ms	-8.9%

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

---

Legend

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

[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!