fix(pool): cwdInWorktree accepts dot-prefixed subdirectories

[e-jung]

Intent

treehouse status fails to recognize the user as "here" when their cwd is inside a dot-prefixed subdirectory of a worktree (e.g. <worktree>/.venv, <worktree>/.cache, <worktree>/.git-hooks).

The cwdInWorktree predicate rejected any relative path whose first character is a dot, so .venv/bin (relative path .venv/bin) was treated as "not in the worktree", suppressing the "you're here" marker on the owning worktree in status output.

This is a status-display-only bug — no data loss, no acquisition/release behavior change. Very low risk.

Approach

The cwdInWorktree predicate ended with:

return rel == "." || !filepath.IsAbs(rel) && len(rel) >= 1 && rel[0] != '.'

The rel[0] != '.' check was meant to reject .. escapes but also rejected every dot-prefixed subdir (.venv, .cache, .git-hooks, ...). The correct, minimal predicate already exists in-repo at internal/process/detect.go:75:

rel != ".." && !strings.HasPrefix(rel, ".."+string(filepath.Separator))

Apply that same predicate in cwdInWorktree: the cwd is in the worktree when rel == "." (the root) or rel does not start with .. (does not escape the root). Dot-prefixed subdirectories like .venv/bin satisfy this and are now correctly recognized.

Scope

Two files, +46 / -1:

• internal/pool/pool.go — cwdInWorktree uses the same "does not escape via .." predicate as internal/process/detect.go; adds the strings import.
• internal/pool/pool_test.go — first test for cwdInWorktree, a table-driven TestCwdInWorktree covering: worktree root (.), regular subdir (src/foo), dot-prefixed subdirs (.venv/bin, .cache/tmp — the bug case), the worktree parent (..), and a sibling directory.

Risk

Very low. cwdInWorktree only drives the "you're here" (StatusHere) marker in status output — it is not on the acquisition, release, prune, or destroy paths. The new predicate matches the one already validated in internal/process/detect.go. No data-loss surface; no behavioral change beyond the status marker.

Verification

• New TestCwdInWorktree passes on the fixed code.
• Confirmed the test has teeth: against the old predicate, the two dot-prefixed subdirectory cases (/.venv/bin, /.cache/tmp) fail with = false, want true, while the root / regular-subdir / outside / sibling cases pass — exactly the regression the fix targets.
• Full suite green: go test ./... (cmd, internal/config, internal/git, internal/hooks, internal/pool, internal/process, internal/updater).
• go vet ./... clean; gofmt clean.

Regression test transcript (buggy vs fixed)

=== Against BUGGY predicate (rel[0] != '.') ===
--- PASS: TestCwdInWorktree/worktree_root
--- PASS: TestCwdInWorktree/regular_subdir
--- FAIL: TestCwdInWorktree/dot-prefixed_subdir_.venv/bin   (false, want true)
--- FAIL: TestCwdInWorktree/dot-prefixed_subdir_.cache/tmp  (false, want true)
--- PASS: TestCwdInWorktree/parent_of_worktree_(rel_starts_with_..)
--- PASS: TestCwdInWorktree/sibling_dir
FAIL

=== Against FIXED predicate ===
--- PASS: TestCwdInWorktree/worktree_root
--- PASS: TestCwdInWorktree/regular_subdir
--- PASS: TestCwdInWorktree/dot-prefixed_subdir_.venv/bin
--- PASS: TestCwdInWorktree/dot-prefixed_subdir_.cache/tmp
--- PASS: TestCwdInWorktree/parent_of_worktree_(rel_starts_with_..)
--- PASS: TestCwdInWorktree/sibling_dir
PASS

AI disclosure

Human-reviewed. The investigation (locating the predicate and its correct counterpart in internal/process/detect.go), the fix, and the regression test were produced autonomously and reviewed by a human operator before opening.