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/steps/shell/__init__.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 import json
 import math
+import os
 import subprocess
 from typing import Any
 
@@ -40,6 +41,13 @@ class ShellStep(StepBase):
                 error=timeout_error,
                 output={"exit_code": -1, "stdout": "", "stderr": "invalid timeout"},
             )
+
+        env = {**os.environ}
+        if context.workflow_dir:
+            env["SPECKIT_WORKFLOW_DIR"] = context.workflow_dir
+        else:
+            env.pop("SPECKIT_WORKFLOW_DIR", None)
+
         # NOTE: shell=True is required to support pipes, redirects, and
         # multi-command expressions in workflow YAML.  Workflow authors
         # control commands; catalog-installed workflows should be reviewed
@@ -51,6 +59,7 @@ class ShellStep(StepBase):
                 capture_output=True,
                 text=True,
                 cwd=cwd,
+                env=env,
                 timeout=timeout,
             )
             output = {