feat: implement per-note search and document pipeline

- Add SourceType::Note with extract_note_document() and ParentMetadataCache
- Migration 022: composite indexes for notes queries + author_id column
- Migration 024: table rebuild adding 'note' to CHECK constraints, defense triggers
- Migration 025: backfill existing non-system notes into dirty queue
- Add lore notes CLI command with 17 filter options (author, path, resolution, etc.)
- Support table/json/jsonl/csv output formats with field selection
- Wire note dirty tracking through discussion and MR discussion ingestion
- Fix test_migration_024_preserves_existing_data off-by-one (tested wrong migration)
- Fix upsert_document_inner returning false for label/path-only changes

src/cli/robot.rs

@@ -64,6 +64,10 @@ pub fn expand_fields_preset(fields: &[String], entity: &str) -> Vec<String> {
                 .iter()
                 .map(|s| (*s).to_string())
                 .collect(),
+            "notes" => ["id", "author_username", "body", "created_at_iso"]
+                .iter()
+                .map(|s| (*s).to_string())
+                .collect(),
             _ => fields.to_vec(),
         }
     } else {
@@ -82,3 +86,25 @@ pub fn strip_schemas(commands: &mut serde_json::Value) {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_expand_fields_preset_notes() {
+        let fields = vec!["minimal".to_string()];
+        let expanded = expand_fields_preset(&fields, "notes");
+        assert_eq!(
+            expanded,
+            ["id", "author_username", "body", "created_at_iso"]
+        );
+    }
+
+    #[test]
+    fn test_expand_fields_preset_passthrough() {
+        let fields = vec!["id".to_string(), "body".to_string()];
+        let expanded = expand_fields_preset(&fields, "notes");
+        assert_eq!(expanded, ["id", "body"]);
+    }
+}