feat(quotesdb): add generate_id() using UUID v4 — WASM-compatible ID generation

- Add uuid = { version = "1", features = ["v4", "serde"] } to [dependencies]
- Add getrandom = { version = "0.4", features = ["wasm_js"] } under wasm32 cfg
- Implement generate_id() in src/lib.rs with rustdoc and doctest
- Add unit tests for length, hyphen count, and uniqueness

Closes ticket 7a0d9f

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

quotesdb/Cargo.toml

@@ -15,6 +15,10 @@ path = "src/bin/ui/main.rs"
 
 [dependencies]
 common = { path = "../common" }
+uuid = { version = "1", features = ["v4", "serde"] }
+
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+getrandom = { version = "0.4", features = ["wasm_js"] }
 
 [dev-dependencies]
 

quotesdb/src/lib.rs

@@ -6,3 +6,48 @@
 //!
 //! Use `#[cfg(not(target_arch = "wasm32"))]` for host-only items
 //! and `#[cfg(target_arch = "wasm32")]` for wasm-only items.
+
+/// Generates a new UUID v4 string for use as a database primary key.
+///
+/// Returns a 36-character hyphenated UUID string. Compatible with both
+/// native and `wasm32-unknown-unknown` targets (uses Web Crypto API via
+/// `getrandom/wasm_js` on WASM).
+///
+/// # Examples
+///
+/// ```
+/// let id = quotesdb::generate_id();
+/// assert_eq!(id.len(), 36);
+/// assert_eq!(id.chars().filter(|&c| c == '-').count(), 4);
+/// ```
+pub fn generate_id() -> String {
+    uuid::Uuid::new_v4().to_string()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_generate_id_length() {
+        let id = generate_id();
+        assert_eq!(id.len(), 36, "UUID v4 must be 36 characters");
+    }
+
+    #[test]
+    fn test_generate_id_hyphen_count() {
+        let id = generate_id();
+        assert_eq!(
+            id.chars().filter(|&c| c == '-').count(),
+            4,
+            "UUID v4 must contain exactly 4 hyphens"
+        );
+    }
+
+    #[test]
+    fn test_generate_id_uniqueness() {
+        let id1 = generate_id();
+        let id2 = generate_id();
+        assert_ne!(id1, id2, "Two generated IDs must be different");
+    }
+}