gstack-slug derived everything from pwd, so a session in a subdirectory got
the subdir's basename as its slug (or an outer monorepo's remote), misfiling
reviews/decisions/learnings under a phantom project — and the per-pwd cache
made the wrong answer permanent. The resolver now walks up from pwd:
outermost STRONG marker wins (.git, package.json, pyproject.toml, Cargo.toml,
Gemfile, go.mod, .project.yaml), weak content markers (README, LICENSE) catch
non-code project folders, deploy artifacts are deliberately not markers, and
GSTACK_PROJECT_SLUG remains the escape hatch. The cache self-heals on
mismatch. Main-side invariants preserved on top: the unconditional
[a-zA-Z0-9._-] re-sanitize before echo and slash→dash branch canonicalization.
Fixes#1125.
Contributed by @ajeenkya (PR #1702; rebased over the sanitize and
branch-canonicalization work that landed after it).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>