feat(cli): add specify self check and self upgrade stub

src/specify_cli/__init__.py

@@ -7,6 +7,8 @@
 #     "platformdirs",
 #     "readchar",
 #     "json5",
+#     "pyyaml",
+#     "packaging",
 # ]
 # ///
 """
@@ -34,8 +36,12 @@
 import json5
 import stat
 import shlex
+import urllib.error
+import urllib.request
 import yaml
 from pathlib import Path
+
+from packaging.version import InvalidVersion, Version
 from typing import Any, Optional
 
 import typer
@@ -51,6 +57,8 @@
 # For cross-platform keyboard input
 import readchar
 
+GITHUB_API_LATEST = "https://api.github.com/repos/github/spec-kit/releases/latest"
+
 def _build_agent_config() -> dict[str, dict[str, Any]]:
     """Derive AGENT_CONFIG from INTEGRATION_REGISTRY."""
     from .integrations import INTEGRATION_REGISTRY
@@ -318,7 +326,7 @@ def run_selection_loop():
 
     return selected_key
 
-console = Console()
+console = Console(highlight=False)
 
 class BannerGroup(TyperGroup):
     """Custom group that shows banner before help."""
@@ -1599,25 +1607,10 @@ def check():
 def version():
     """Display version and system information."""
     import platform
-    import importlib.metadata
 
     show_banner()
 
-    # Get CLI version from package metadata
-    cli_version = "unknown"
-    try:
-        cli_version = importlib.metadata.version("specify-cli")
-    except Exception:
-        # Fallback: try reading from pyproject.toml if running from source
-        try:
-            import tomllib
-            pyproject_path = Path(__file__).parent.parent.parent / "pyproject.toml"
-            if pyproject_path.exists():
-                with open(pyproject_path, "rb") as f:
-                    data = tomllib.load(f)
-                    cli_version = data.get("project", {}).get("version", "unknown")
-        except Exception:
-            pass
+    cli_version = get_speckit_version()
 
     info_table = Table(show_header=False, box=None, padding=(0, 2))
     info_table.add_column("Key", style="cyan", justify="right")
@@ -1640,6 +1633,162 @@ def version():
     console.print(panel)
     console.print()
 
+def _get_installed_version() -> str:
+    """Return the installed specify-cli distribution version or 'unknown'.
+
+    Uses importlib.metadata so the value reflects what was actually installed
+    by pip/uv/pipx — not a value read from pyproject.toml. This is
+    intentional for `specify self check`, which should reason about the
+    installed distribution rather than a source-tree fallback. Callers must
+    treat the sentinel string 'unknown' as an indeterminate value (see FR-020).
+    """
+
+    import importlib.metadata
+
+    metadata_errors = [importlib.metadata.PackageNotFoundError]
+    invalid_metadata_error = getattr(importlib.metadata, "InvalidMetadataError", None)
+    if invalid_metadata_error is not None:
+        metadata_errors.append(invalid_metadata_error)
+
+    try:
+        return importlib.metadata.version("specify-cli")
+    except tuple(metadata_errors):
+        return "unknown"
+
+def _normalize_tag(tag: str) -> str:
+    """Strip exactly one leading 'v' from a release tag.
+
+    Returns the rest of the string unchanged. This handles the common
+    'vX.Y.Z' tag convention in this repo; it MUST NOT strip more
+    aggressively (e.g., two leading 'v's keeps one).
+    """
+    return tag[1:] if tag.startswith("v") else tag
+
+def _is_newer(latest: str, current: str) -> bool:
+    """Return True iff `latest` is strictly greater than `current` under PEP 440.
+
+    Returns False whenever either side is 'unknown' or fails to parse; this
+    keeps the comparison indeterminate (rather than crashing or falsely
+    recommending a downgrade) on edge inputs.
+    """
+    if latest == "unknown" or current == "unknown":
+        return False
+    try:
+        return Version(latest) > Version(current)
+    except InvalidVersion:
+        return False
+
+
+def _fetch_latest_release_tag() -> tuple[str | None, str | None]:
+    """Return (tag, failure_category). Exactly one outbound call, 5 s timeout.
+
+    On success: (tag_name, None).
+    On a documented network/HTTP failure (added in T029/T030): (None, category).
+    On anything else — including a malformed response body — the exception
+    propagates; there is no catch-all (research D-006).
+    """
+    req = urllib.request.Request(
+        GITHUB_API_LATEST,
+        headers={"Accept": "application/vnd.github+json"},
+    )
+    token = None
+    for env_var in ("GH_TOKEN", "GITHUB_TOKEN"):
+        candidate = os.environ.get(env_var)
+        if candidate is not None:
+            candidate = candidate.strip()
+            if candidate:
+                token = candidate
+                break
+    if token:
+        req.add_header("Authorization", f"Bearer {token}")
+    try:
+        with urllib.request.urlopen(req, timeout=5) as resp:
+            payload = json.loads(resp.read().decode("utf-8"))
+            tag = payload.get("tag_name")
+            if not isinstance(tag, str) or not tag:
+                raise ValueError("GitHub API response missing valid tag_name")
+            return tag, None
+    except urllib.error.HTTPError as e:
+        # Order matters: HTTPError is a subclass of URLError.
+        if e.code == 403:
+            return None, "rate limited (try setting GH_TOKEN or GITHUB_TOKEN)"
+        return None, f"HTTP {e.code}"
+    except (urllib.error.URLError, OSError):
+        return None, "offline or timeout"
+
+
+# ===== Self Commands =====
+self_app = typer.Typer(
+    name="self",
+    help="Manage the specify CLI itself (read-only check and reserved upgrade command).",
+    add_completion=False,
+)
+app.add_typer(self_app, name="self")
+
+@self_app.command("check")
+def self_check() -> None:
+    """Check whether a newer specify-cli release is available. Read-only.
+
+    This command only checks for updates; it does not modify your installation.
+    The reserved (and currently non-destructive) `specify self upgrade` command
+    is the name that a future release will use for actual self-upgrade — its
+    behavior is not implemented in this release and is intentionally out of
+    scope here. See `specify self upgrade --help` for its current status.
+    """
+
+    installed = _get_installed_version()
+    tag, failure_reason = _fetch_latest_release_tag()
+
+    if tag is None:
+        # Graceful-failure path (FR-008). `failure_reason` is one of the
+        # enumerated strings produced by _fetch_latest_release_tag() — it
+        # never contains a URL, headers, response body, or traceback.
+        console.print(f"Installed: {installed}")
+        console.print(f"[yellow]Could not check latest release:[/yellow] {failure_reason}")
+        return
+
+    latest_normalized = _normalize_tag(tag)
+
+    if installed == "unknown":
+        # FR-020: surface the latest release and the recovery action even
+        # when the local distribution metadata is unavailable.
+        console.print("Current version could not be determined.")
+        console.print(f"Latest release: {latest_normalized}")
+        console.print("\nTo reinstall:")
+        console.print("  uv tool install specify-cli --force \\")
+        console.print(f"    --from git+https://github.com/github/spec-kit.git@{tag}")
+        return
+
+    if _is_newer(latest_normalized, installed):
+        console.print(f"[green]Update available:[/green] {installed} → {latest_normalized}")
+        console.print("\nTo upgrade:")
+        console.print("  uv tool install specify-cli --force \\")
+        console.print(f"    --from git+https://github.com/github/spec-kit.git@{tag}")
+        return
+
+    # Installed is parseable AND is >= latest → "up to date" (FR-006).
+    # Also reached when the tag is unparseable (InvalidVersion) → _is_newer
+    # returns False, and the up-to-date branch is the safer default per
+    # FR-004 / test T016.
+    console.print(f"[green]Up to date:[/green] {installed}")
+
+
+@self_app.command("upgrade")
+def self_upgrade() -> None:
+    """Reserved command surface for self-upgrade; not implemented in this release.
+
+    This command is a documented non-destructive stub in this release: it
+    performs no outbound network request, no install-method detection, and
+    invokes no installer. It prints a three-line guidance message and exits 0.
+    Actual self-upgrade is planned as follow-up work.
+
+    Use `specify self check` today to see whether a newer release is available
+    and to get a copy-pasteable reinstall command.
+    """
+    console.print("specify self upgrade is not implemented yet.")
+    console.print("Run 'specify self check' to see whether a newer release is available.")
+    console.print("Actual self-upgrade is planned as follow-up work.")
+
 
 # ===== Extension Commands =====