Fix crash on git dependencies: key "path" not found (#90)

## Problem

`_generate_hub_and_spokes` crashes with `key "path" not found in
dictionary` when a workspace member has git dependencies in Cargo.toml:

```toml
[dependencies]
ruff_python_parser = { git = "https://github.com/astral-sh/ruff.git", tag = "0.15.10" }
```

The crash is at `extensions.bzl:1028`:
```starlark
bazel_target = "//" + paths.join(workspace_package, _normalize_path(dep["path"]).removeprefix(repo_root + "/"))
```

Git deps don't have a `path` field — only path deps (workspace members)
do.

## Fix

Check for `dep.get("path")` before accessing it. Git/registry deps
without a `bazel_target` are resolved elsewhere as external crate repos,
so we skip them in the path-dep resolution path.

## Testing

Tested with a real-world workspace (ppl-ai/agi) that has a crate
depending on `ruff_python_parser` via git. Before: `bazel mod tidy`
crashes. After: builds successfully.

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: longlho

rs/extensions.bzl

@@ -1025,7 +1025,12 @@ RESOLVED_PLATFORMS = select({{
         for dep in package["dependencies"]:
             bazel_target = dep.get("bazel_target")
             if not bazel_target:
-                bazel_target = "//" + paths.join(workspace_package, _normalize_path(dep["path"]).removeprefix(repo_root + "/"))
+                dep_path = dep.get("path")
+                if not dep_path:
+                    # Git or registry deps without a bazel_target are resolved
+                    # elsewhere (e.g., as external crate repos). Skip here.
+                    continue
+                bazel_target = "//" + paths.join(workspace_package, _normalize_path(dep_path).removeprefix(repo_root + "/"))
 
             if dep.get("rename"):
                 aliases[bazel_target] = dep["rename"].replace("-", "_")

test/MODULE.bazel

@@ -150,6 +150,7 @@ TESTS = [
     "workspace_path_dependency",
     "workspace_hyphen_dep_aliases",
     "workspace_renamed_path_dep_aliases",
+    "workspace_git_dep",
     "binaries",
     "uv",
 ]

test/workspace_git_dep/Cargo.lock

@@ -0,0 +1,3 @@
+[workspace]
+members = ["app"]
+resolver = "3"

test/workspace_git_dep/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "app"
+version = "0.1.0"
+edition = "2024"
+
+[lib]
+
+[dependencies]
+itoa = { git = "https://github.com/dtolnay/itoa", tag = "1.0.14" }

test/workspace_git_dep/app/Cargo.toml

@@ -0,0 +1 @@
+// Smoke test: workspace member with a git dependency.