Project-local .claude/skills/gstack install breaks /browse and setup can report false success

[morluto]

While auditing the install/deploy path end to end, I found a reproducible issue in the README-supported project install flow.

Summary

• A repo-local install at .claude/skills/gstack can break /browse if there is no matching user-level install under ~/.claude/skills/gstack.
• Separately, ./setup can print gstack ready even when browse/dist/browse was not actually produced.

Why this matters

• The README explicitly positions project-local install as a supported path for teammates.
• In practice, a clean repo-level install can leave /browse unusable, which makes the deploy story look successful when it is not.

Repro

1. Install gstack only at the project level (for example .claude/skills/gstack) and do not keep a user-level ~/.claude/skills/gstack install around.
2. Run ./setup from that project-local gstack directory.
3. Run the compiled binary from that project-local install.

Observed behavior

• The compiled CLI can fail trying to resolve server.ts from ~/.claude/skills/gstack/browse/src/server.ts instead of from the adjacent project-local install.
• In my audit, ./setup also printed gstack ready even when browse/dist/browse was still missing.

Expected behavior

• A project-local install should be self-contained: compiled browse should resolve its server script from the installed repo it lives in.
• ./setup should exit non-zero if the binary is still missing after the build step.
• ./setup should also rebuild when source files are newer than the compiled binary, not only when the binary is missing.

Root cause

• browse/src/cli.ts falls back to path.resolve(process.env.HOME || "/tmp", ".claude/skills/gstack/browse/src/server.ts") when running from the compiled binary, so the runtime assumes a user-level install exists.
• setup only checked if [ ! -x "$GSTACK_DIR/browse/dist/browse" ] before building, and it did not verify the artifact existed afterward.

I validated a fix locally by:

• resolving server.ts from the compiled binary's adjacent browse/src/server.ts first,
• keeping the env override and HOME fallback,
• making setup fail hard if browse/dist/browse is still missing,
• and adding regression coverage for the compiled project-install path.