refactor: extract shared lint record primitives

crates/lint-common/src/lib.rs

@@ -0,0 +1,20 @@
+//! Shared record lint primitives for memory and workflow files.
+
+mod frontmatter;
+mod slug;
+
+pub use frontmatter::{Frontmatter, split_frontmatter};
+pub use slug::{Slug, is_valid_slug};
+
+/// Common lint errors for Markdown record syntax shared by memory and workflow.
+#[derive(Debug, Clone, thiserror::Error, PartialEq, Eq)]
+pub enum RecordLintError {
+    #[error("invalid slug `{0}`: must match ^[a-z0-9](?:[a-z0-9-]{{0,62}}[a-z0-9])?$")]
+    InvalidSlug(String),
+
+    #[error("malformed frontmatter: {0}")]
+    MalformedFrontmatter(String),
+
+    #[error("frontmatter is missing or document is empty")]
+    MissingFrontmatter,
+}