feat(project): Add substring matching and use Ambiguous error for resolution

Extend resolve_project() with a 4th cascade step: case-insensitive
substring match when exact, case-insensitive, and suffix matches all
fail. This allows shorthand like "typescript" to match
"vs/typescript-code" when unambiguous. Multi-match still returns an
error with all candidates listed.

Also change ambiguity errors from LoreError::Other to LoreError::Ambiguous
so they get the proper AMBIGUOUS error code (exit 18) instead of
INTERNAL_ERROR.

Includes tests for unambiguous substring, case-insensitive substring,
ambiguous substring, and suffix-preferred-over-substring ordering.

Co-Authored-By: Claude (us.anthropic.claude-opus-4-5-20251101-v1:0) <noreply@anthropic.com>

src/core/project.rs

@@ -5,8 +5,9 @@ use super::error::{LoreError, Result};
 /// Resolve a project string to a project_id using cascading match:
 /// 1. Exact match on path_with_namespace
 /// 2. Case-insensitive exact match
-/// 3. Suffix match (only if unambiguous)
+/// 3. Suffix match (e.g., "auth-service" matches "group/auth-service") — only if unambiguous
-/// 4. Error with available projects list
+/// 4. Substring match (e.g., "typescript" matches "vs/typescript-code") — only if unambiguous
+/// 5. Error with available projects list
 pub fn resolve_project(conn: &Connection, project_str: &str) -> Result<i64> {
     // Step 1: Exact match
     let exact = conn.query_row(
@@ -44,7 +45,7 @@ pub fn resolve_project(conn: &Connection, project_str: &str) -> Result<i64> {
         1 => return Ok(suffix_matches[0].0),
         n if n > 1 => {
             let matching: Vec<String> = suffix_matches.iter().map(|(_, p)| p.clone()).collect();
-            return Err(LoreError::Other(format!(
+            return Err(LoreError::Ambiguous(format!(
                 "Project '{}' is ambiguous. Matching projects:\n{}\n\nHint: Use the full path, e.g., --project={}",
                 project_str,
                 matching.iter().map(|p| format!("  {}", p)).collect::<Vec<_>>().join("\n"),
@@ -54,7 +55,32 @@ pub fn resolve_project(conn: &Connection, project_str: &str) -> Result<i64> {
         _ => {}
     }
 
-    // Step 4: No match — list available projects
+    // Step 4: Case-insensitive substring match (unambiguous)
+    let mut substr_stmt = conn.prepare(
+        "SELECT id, path_with_namespace FROM projects
+         WHERE LOWER(path_with_namespace) LIKE '%' || LOWER(?1) || '%'"
+    )?;
+    let substr_matches: Vec<(i64, String)> = substr_stmt
+        .query_map(rusqlite::params![project_str], |row| {
+            Ok((row.get(0)?, row.get(1)?))
+        })?
+        .collect::<std::result::Result<Vec<_>, _>>()?;
+
+    match substr_matches.len() {
+        1 => return Ok(substr_matches[0].0),
+        n if n > 1 => {
+            let matching: Vec<String> = substr_matches.iter().map(|(_, p)| p.clone()).collect();
+            return Err(LoreError::Ambiguous(format!(
+                "Project '{}' is ambiguous. Matching projects:\n{}\n\nHint: Use the full path, e.g., --project={}",
+                project_str,
+                matching.iter().map(|p| format!("  {}", p)).collect::<Vec<_>>().join("\n"),
+                matching[0]
+            )));
+        }
+        _ => {}
+    }
+
+    // Step 5: No match — list available projects
     let mut all_stmt = conn.prepare(
         "SELECT path_with_namespace FROM projects ORDER BY path_with_namespace"
     )?;
@@ -143,6 +169,48 @@ mod tests {
         assert!(msg.contains("frontend/auth-service"));
     }
 
+    #[test]
+    fn test_substring_unambiguous() {
+        let conn = setup_db();
+        insert_project(&conn, 1, "vs/python-code");
+        insert_project(&conn, 2, "vs/typescript-code");
+        let id = resolve_project(&conn, "typescript").unwrap();
+        assert_eq!(id, 2);
+    }
+
+    #[test]
+    fn test_substring_case_insensitive() {
+        let conn = setup_db();
+        insert_project(&conn, 1, "vs/python-code");
+        insert_project(&conn, 2, "vs/typescript-code");
+        let id = resolve_project(&conn, "TypeScript").unwrap();
+        assert_eq!(id, 2);
+    }
+
+    #[test]
+    fn test_substring_ambiguous() {
+        let conn = setup_db();
+        insert_project(&conn, 1, "vs/python-code");
+        insert_project(&conn, 2, "vs/typescript-code");
+        // "code" matches both projects
+        let err = resolve_project(&conn, "code").unwrap_err();
+        let msg = err.to_string();
+        assert!(msg.contains("ambiguous"), "Expected ambiguous error, got: {}", msg);
+        assert!(msg.contains("vs/python-code"));
+        assert!(msg.contains("vs/typescript-code"));
+    }
+
+    #[test]
+    fn test_suffix_preferred_over_substring() {
+        // Suffix match (step 3) should resolve before substring (step 4)
+        let conn = setup_db();
+        insert_project(&conn, 1, "backend/auth-service");
+        insert_project(&conn, 2, "backend/auth-service-v2");
+        // "auth-service" is an exact suffix of project 1
+        let id = resolve_project(&conn, "auth-service").unwrap();
+        assert_eq!(id, 1);
+    }
+
     #[test]
     fn test_no_match() {
         let conn = setup_db();