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/gitlab/transformers/discussion.rs

@@ -30,6 +30,7 @@ pub struct NormalizedNote {
     pub project_id: i64,
     pub note_type: Option<String>,
     pub is_system: bool,
+    pub author_id: Option<i64>,
     pub author_username: String,
     pub body: String,
     pub created_at: i64,
@@ -160,6 +161,7 @@ fn transform_single_note(
         project_id: local_project_id,
         note_type: note.note_type.clone(),
         is_system: note.system,
+        author_id: Some(note.author.id),
         author_username: note.author.username.clone(),
         body: note.body.clone(),
         created_at: parse_timestamp(&note.created_at),
@@ -265,6 +267,7 @@ fn transform_single_note_strict(
         project_id: local_project_id,
         note_type: note.note_type.clone(),
         is_system: note.system,
+        author_id: Some(note.author.id),
         author_username: note.author.username.clone(),
         body: note.body.clone(),
         created_at,