Greptile Summary

This PR relocates Global.Path.bin from the XDG data directory to the XDG cache directory and ensures tools installed there are discoverable by appending the path to PATH inside which(). The motivation is correct — npm-installed tools should be found by which() — but moving bin into the cache directory introduces a silent regression where all installed tools are wiped whenever CACHE_VERSION changes.

Key changes:

• global/index.ts: bin path changed from path.join(data, "bin") to path.join(cache, "bin")
• which.ts: Builds a composite PATH string that appends Global.Path.bin to the inherited environment PATH before resolving commands

Issues found:

• The cache-invalidation block in global/index.ts deletes all contents of Global.Path.cache on version bumps. Since bin is now a subdirectory of cache, installed tools will be silently deleted on any future CACHE_VERSION change, breaking tool discovery until they are reinstalled — and there is no visible reinstallation logic triggered after a wipe.
• Minor style note: the full variable in which.ts is used only once and should be inlined per the project style guide.

Confidence Score: 3/5

• Mergeable in concept, but the cache-invalidation interaction will silently wipe installed tools on any future CACHE_VERSION bump.
• The which() fix is correct and the intent of the bin relocation is sound, but placing bin inside the cache directory without excluding it from cache wipes creates a latent regression that will surface on the next version bump. This needs to be addressed before merging.
• packages/opencode/src/global/index.ts — cache-invalidation logic needs to skip or handle the bin subdirectory.

Important Files Changed

Sequence Diagram

sequenceDiagram
    participant Caller
    participant which
    participant whichPkg
    participant Global

    Caller->>which: which(cmd, env?)
    which->>Global: Global.Path.bin
    Global-->>which: ~/.cache/opencode/bin
    which->>which: base = env.PATH ?? process.env.PATH ?? ""
    which->>which: full = base + ":" + ~/.cache/opencode/bin
    which->>whichPkg: sync(cmd, { path: full })
    whichPkg-->>which: resolved path | null
    which-->>Caller: string | null

_{Last reviewed commit: "fix: include cache b..."}