test: add pet-homebrew locator coverage

[karthiknadig]

Adds focused pet-homebrew unit tests as a small follow-up slice from the broader coverage plan.

• Cover Homebrew locator metadata and Linuxbrew identification
• Cover non-Homebrew, virtualenv, and Conda rejection paths
• Cover Homebrew path classification and HOMEBREW_PREFIX bin discovery
• Keep this PR scoped to pet-homebrew only

Fixes #393
Part of #389

[github-actions]

Test Coverage Report (Linux)

Metric	Value
Current Coverage	73.2%
Base Branch Coverage	72.0%
Delta	1.2% ✅

---

Coverage increased! Great work!

[github-actions]

Performance Report (Linux) ➖

Metric	PR (P50)	PR (P95)	Baseline (P50)	Delta	Change
Server Startup	1ms	1ms	1ms	0ms	0%
Full Refresh	78ms	136ms	75ms	3ms	0%

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 (macOS)

Metric	PR (P50)	PR (P95)	Baseline (P50)	Delta
Server Startup	70ms	701ms	67ms	3ms
Full Refresh	137ms	31199ms	142ms	-5ms

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	9ms	12ms	8ms	1ms	12.5%
Full Refresh	146ms	379ms	143ms	3ms	2.1%

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	69.41%
Base Branch Coverage	68.72%
Delta	0.69% ✅

---

Coverage increased! Great work!

[Copilot]

Pull request overview

Adds focused unit tests to the pet-homebrew locator crate to improve branch coverage for Homebrew/Linuxbrew identification and helper logic, aligning with the broader workspace coverage plan.

Changes:

• Add unit tests for Homebrew path recognition and symlink template behavior in sym_links.
• Add locator-level tests for Homebrew kind/category metadata, Linuxbrew identification, and rejection of non-Homebrew/virtualenv/Conda inputs.
• Add tests for HOMEBREW_PREFIX-driven prefix bin discovery behavior.

Show a summary per file

File	Description
crates/pet-homebrew/src/sym_links.rs	Adds tests for Homebrew/Linuxbrew path classification and symlink helper branches.
crates/pet-homebrew/src/lib.rs	Adds locator-focused tests for identification and rejection paths (non-homebrew, venv, conda).
crates/pet-homebrew/src/environment_locations.rs	Adds tests for HOMEBREW_PREFIX bin discovery logic.

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 2

[Copilot]

Pull request overview

This PR adds targeted unit tests to the pet-homebrew crate to improve branch coverage for Homebrew/Linuxbrew environment identification and related helper functions, aligning with the broader coverage plan while staying crate-scoped.

Changes:

• Add unit tests for Homebrew path recognition and known-symlink helper behavior.
• Add unit tests for the Homebrew Locator metadata and try_from rejection/acceptance paths (including Linuxbrew identification).
• Add unit tests for HOMEBREW_PREFIX bin discovery logic, plus tempfile as a dev-dependency.

Show a summary per file

File	Description
crates/pet-homebrew/src/sym_links.rs	Adds unit tests for Homebrew path classification and symlink template helper behavior.
crates/pet-homebrew/src/lib.rs	Adds unit tests for Homebrew locator kind/category and try_from accept/reject paths.
crates/pet-homebrew/src/environment_locations.rs	Adds unit tests for HOMEBREW_PREFIX-driven bin discovery behavior.
crates/pet-homebrew/Cargo.toml	Adds tempfile dev-dependency to support filesystem-backed tests.

Copilot's findings

• Files reviewed: 4/4 changed files
• Comments generated: 1