feat(workflows): expose workflow source directory to steps (#3469)

* feat(workflows): expose workflow source directory to steps (#3467)

Propagate WorkflowDefinition.source_path to steps via
{{ context.workflow_dir }} in template expressions and
SPECKIT_WORKFLOW_DIR env var for shell steps. The original
source directory is persisted in state.json so resume
restores the correct value instead of the run-directory copy path.

Closes #3467

Assisted-By: 🤖 Claude Code

* fix: apply bot review suggestions (#2)

Applied fixes from bot review comments:
- Comment #3563319058: prevent stale SPECKIT_WORKFLOW_DIR leak from parent env
- Comment #3563319094: use cross-platform Python one-liner instead of printenv
- Comment #3563319103: add monkeypatch.delenv for deterministic env var test
- Comment #3563319116: same env leak fix as #3563319058

Assisted-By: 🤖 Claude Code

* fix: use YAML single-quotes and forward-slash paths for Windows CI (#2)

sys.executable on Windows returns backslash paths (D:\a\...) which YAML
double-quoted strings interpret as escape sequences. Switch to
single-quoted YAML strings and normalize paths with replace("\\", "/").

Assisted-By: 🤖 Claude Code

* fix: resolve workflow_dir to absolute path and add installed-by-ID test (#3469)

Applied fixes from bot review comments:
- Comment #3563382853: resolve source_path before taking parent to ensure absolute paths
- Comment #3563382864: add test for installed-by-ID workflow_dir semantics

Assisted-By: 🤖 Claude Code

* docs: document context.workflow_dir and SPECKIT_WORKFLOW_DIR

Add reference documentation for the new workflow_dir runtime value in
both workflows/README.md and docs/reference/workflows.md so workflow
authors can discover the feature and its semantics.

Assisted-By: 🤖 Claude Code

* fix: clarify installed workflow_dir is an absolute path (#3469)

The documentation for context.workflow_dir described the installed-by-ID
case as ".specify/workflows/<id>/" which appears relative, contradicting
the "resolved absolute path" semantics. Clarified that it is the absolute
path to the installation directory.

Assisted-By: 🤖 Claude Code

* fix: apply bot review suggestions (#3469)

Applied fixes from bot review comments:
- Comment #3580005128: Quote sys.executable in shell step env var test
- Comment #3580005174: Quote sys.executable in no-env-var test

Assisted-By: 🤖 Claude Code

* fix: apply bot review suggestions (#3469)

Applied fixes from bot review comments:
- Comment #3587146944: Quote interpolated workflow_dir path in example

Assisted-By: 🤖 Claude Code

src/specify_cli/workflows/expressions.py

@@ -142,7 +142,8 @@ def _build_namespace(context: Any) -> dict[str, Any]:
     # runs use an 8-character uuid4 hex; operator-supplied ids may be
     # any alphanumeric string with hyphens or underscores.
     run_id = getattr(context, "run_id", None) or ""
-    ns["context"] = {"run_id": run_id}
+    workflow_dir = getattr(context, "workflow_dir", None) or ""
+    ns["context"] = {"run_id": run_id, "workflow_dir": workflow_dir}
     return ns