* feat(scripts): add SPECIFY_INIT_DIR to target a member project from the repo root
Resolve an explicit SPECIFY_INIT_DIR project override once in the core
get_repo_root / Get-RepoRoot, so a non-interactive / CI caller can target a
member project (the directory containing .specify/) from a monorepo root
without cd. Strict by design: the path must exist and contain .specify/,
otherwise it hard-errors with no silent fallback.
- Single resolver in core; the git feature-branch script inherits it by
sourcing core, with no per-extension copies.
- PS resolver verifies the resolved path is a directory (Resolve-Path also
succeeds for files) so a file value errors as "not an existing directory".
- get_feature_paths splits decl/assignment so a SPECIFY_INIT_DIR failure
propagates instead of being masked by `local`.
- create-new-feature-branch: when core is absent (only git-common loaded) and
SPECIFY_INIT_DIR is set, hard-error rather than silently using the git root.
- Document SPECIFY_INIT_DIR and SPECIFY_FEATURE_DIRECTORY in the core reference.
- Tests for valid/relative/trailing-slash/file/missing/no-.specify targets,
feature-axis composition, the no-core guard, and a PowerShell mirror.
* fix: guard SPECIFY_INIT_DIR with stale core scripts
* docs: clarify SPECIFY_FEATURE_DIRECTORY precedence wording
* fix: normalize trailing slash in PowerShell SPECIFY_INIT_DIR resolver
Resolve-Path preserves a trailing separator from its input, so a
SPECIFY_INIT_DIR ending in a slash returned a root that didn't match the
bash resolver (whose `cd && pwd` strips it). That broke
test_ps_trailing_slash_tolerated on the CI runners, which do have pwsh.
Trim it with TrimEndingDirectorySeparator (no-op on a bare root or a path
with no trailing separator).
Also fix the misleading test comment: the PowerShell mirror runs on the
CI ubuntu/windows runners (they ship pwsh), it is not skipped there.
* test: normalize bash path expectations on Windows
* docs: clarify SPECIFY_INIT_DIR root helpers
