Detect implicit skill invocations from PowerShell reads (#38228)

## What changed

- Recognize `Get-Content` reads of indexed `SKILL.md` files as implicit skill invocations.
- Support the optional `-Raw` flag, quoted paths containing spaces, and Windows paths without stripping backslashes.

## Testing

- Add unit coverage for the supported `Get-Content` forms and Windows path parsing.

GitOrigin-RevId: 681f2e2fff9a597326bc94b97a31e311ef21b949

codex-rs/skills/src/invocation.rs

@@ -35,6 +35,7 @@ pub fn detect_implicit_skill_invocation_for_command(
     }
 
     detect_skill_doc_read(outcome, tokens.as_slice(), &workdir)
+        .or_else(|| detect_powershell_skill_doc_read(outcome, command, &workdir))
 }
 
 /// Resolves statically recognizable skill accesses without consulting the host filesystem.
@@ -150,6 +151,44 @@ fn detect_skill_doc_read(
     None
 }
 
+fn detect_powershell_skill_doc_read(
+    outcome: &impl ImplicitSkillLookup,
+    command: &str,
+    workdir: &AbsolutePathBuf,
+) -> Option<SkillMetadata> {
+    let path = powershell_get_content_path(command)?;
+    let candidate_path = canonicalize_if_exists(&workdir.join(Path::new(path)));
+    outcome
+        .implicit_skill_for_doc_path(&candidate_path)
+        .cloned()
+}
+
+fn powershell_get_content_path(command: &str) -> Option<&str> {
+    let mut arguments = command.trim().strip_prefix("Get-Content ")?;
+    if let Some(remaining_arguments) = arguments.strip_prefix("-Raw ") {
+        arguments = remaining_arguments;
+    }
+
+    let (path, trailing) = if let Some(quoted_path) = arguments.strip_prefix('"') {
+        let closing_quote = quoted_path.find('"')?;
+        (
+            &quoted_path[..closing_quote],
+            &quoted_path[closing_quote + 1..],
+        )
+    } else {
+        let path_end = arguments
+            .char_indices()
+            .find_map(|(index, character)| character.is_whitespace().then_some(index))
+            .unwrap_or(arguments.len());
+        (&arguments[..path_end], &arguments[path_end..])
+    };
+
+    if path.is_empty() || path.starts_with('-') || !trailing.trim().is_empty() {
+        return None;
+    }
+    Some(path)
+}
+
 fn command_basename(command: &str) -> String {
     Path::new(command)
         .file_name()

codex-rs/skills/src/invocation_tests.rs

@@ -64,6 +64,50 @@ fn script_run_detection_excludes_python_c() {
     assert!(script_run_token(&tokens).is_none());
 }
 
+#[test]
+fn powershell_skill_doc_read_matches_common_forms() {
+    let skill_doc_path = test_path_buf("/tmp/skill-test/SKILL.md").abs();
+    let spaced_skill_doc_path = test_path_buf("/tmp/skill test/SKILL.md").abs();
+    let skill = test_skill_metadata(skill_doc_path.clone());
+    let spaced_skill = test_skill_metadata(spaced_skill_doc_path.clone());
+    let outcome = TestLookup {
+        by_doc_path: HashMap::from([
+            (canonicalize_if_exists(&skill_doc_path), skill),
+            (canonicalize_if_exists(&spaced_skill_doc_path), spaced_skill),
+        ]),
+        ..Default::default()
+    };
+    let path = skill_doc_path.display();
+    let spaced_path = spaced_skill_doc_path.display();
+
+    for command in [
+        format!("Get-Content {path}"),
+        format!("Get-Content -Raw {path}"),
+        format!("Get-Content \"{spaced_path}\""),
+        format!("Get-Content -Raw \"{spaced_path}\""),
+    ] {
+        let found = detect_implicit_skill_invocation_for_command(
+            &outcome,
+            &command,
+            &test_path_buf("/tmp").abs(),
+        );
+
+        assert_eq!(
+            found.map(|value| value.name),
+            Some("test-skill".to_string()),
+            "command: {command}"
+        );
+    }
+}
+
+#[test]
+fn powershell_get_content_path_preserves_windows_backslashes() {
+    assert_eq!(
+        powershell_get_content_path(r#"Get-Content C:\skills\example\SKILL.md"#),
+        Some(r#"C:\skills\example\SKILL.md"#)
+    );
+}
+
 #[test]
 fn skill_doc_read_detection_matches_absolute_path() {
     let skill_doc_path = test_path_buf("/tmp/skill-test/SKILL.md").abs();