fix: skip LFS smudge filter when cloning from bare cache

[lishuceo]

Summary

• Set GIT_LFS_SKIP_SMUDGE=1 env var when cloning from bare cache to workspace, preventing checkout failures on repos with LFS files
• Bare cache repos don't contain LFS objects, so the smudge filter fails trying to download large files from local path

Test plan

• Added regression test verifying GIT_LFS_SKIP_SMUDGE=1 is set in clone env
• All 31 workspace manager tests pass

🤖 Generated with Claude Code

[claude]

Claude finished @lishuceo's task in 57s —— View job

---

PR Review: fix: skip LFS smudge filter when cloning from bare cache

• Check for previous review comments
• Gather context and read changed files
• Review changes and post findings

---

✅ Approved — The core fix is correct and well-tested.

Core Fix (confidence: 95)

The 1-line change in src/workspace/manager.ts:158 correctly sets GIT_LFS_SKIP_SMUDGE=1 when cloning from bare cache. This is the right approach — bare caches don't have LFS objects, so the smudge filter would fail trying to resolve them locally. The env var is applied at the execFileSync level via the env option, which is clean and scoped.

The regression test at manager.test.ts:260-267 properly verifies the env var is set on the clone call.

Observation

🟡 Unrelated files in PR (not blocking): This PR bundles 3 unrelated files with the LFS fix:

• docs/research/prompt-cache-analysis.md — prompt caching cost analysis doc
• scripts/test-cache-optimization.mjs — cache optimization test script
• scripts/test-cache-resume.mjs — cache resume test script

These were added in commit 1e09067 ("research: prompt caching cost analysis and optimization") which is unrelated to the LFS smudge fix. Consider splitting into separate PRs for cleaner history, but this is not a blocker.

Summary

The actual fix (GIT_LFS_SKIP_SMUDGE=1 env var + test) is minimal, correct, and well-scoped. No bugs, security issues, or architectural concerns.