feat: add database models and queries for annotations

- Add MediaNotes and MediaHighlights model structs with pgx v5 types
- Add EbookNotes and EbookHighlights for backward compatibility
- Add complete CRUD SQL queries for notes and highlights
- Add database connection pool function using pgx v5
- Generate sqlc code for new annotation functionality

internal/database/queries/queries.sql

@@ -279,4 +279,102 @@ DELETE FROM media_ratings WHERE media_item_id = $1 AND user_id = $2;
 -- Legacy folder management is now handled through libraries
 
 -- name: GetEbookByFilePath :one
-SELECT * FROM ebooks WHERE file_path = $1;
+SELECT * FROM ebooks WHERE file_path = $1;
+
+-- Media Notes queries
+-- name: CreateMediaNote :one
+INSERT INTO media_notes (media_item_id, user_id, content, position)
+VALUES ($1, $2, $3, $4)
+RETURNING *;
+
+-- name: GetMediaNote :one
+SELECT * FROM media_notes WHERE id = $1;
+
+-- name: GetMediaNotes :many
+SELECT * FROM media_notes WHERE media_item_id = $1 AND user_id = $2 ORDER BY created_at DESC;
+
+-- name: UpdateMediaNote :one
+UPDATE media_notes SET
+    content = $2,
+    position = $3,
+    updated_at = NOW()
+WHERE id = $1
+RETURNING *;
+
+-- name: DeleteMediaNote :exec
+DELETE FROM media_notes WHERE id = $1;
+
+-- Media Highlights queries
+-- name: CreateMediaHighlight :one
+INSERT INTO media_highlights (media_item_id, user_id, selection_text, start_position, end_position, color, note_id)
+VALUES ($1, $2, $3, $4, $5, $6, $7)
+RETURNING *;
+
+-- name: GetMediaHighlight :one
+SELECT * FROM media_highlights WHERE id = $1;
+
+-- name: GetMediaHighlights :many
+SELECT * FROM media_highlights WHERE media_item_id = $1 AND user_id = $2 ORDER BY created_at DESC;
+
+-- name: UpdateMediaHighlight :one
+UPDATE media_highlights SET
+    selection_text = $2,
+    start_position = $3,
+    end_position = $4,
+    color = $5,
+    note_id = $6,
+    updated_at = NOW()
+WHERE id = $1
+RETURNING *;
+
+-- name: DeleteMediaHighlight :exec
+DELETE FROM media_highlights WHERE id = $1;
+
+-- Backward compatibility - Ebook Notes queries (using views)
+-- name: CreateEbookNote :one
+INSERT INTO media_notes (media_item_id, user_id, content, position)
+VALUES ($1, $2, $3, $4)
+RETURNING *;
+
+-- name: GetEbookNote :one
+SELECT * FROM ebook_notes WHERE id = $1;
+
+-- name: GetEbookNotes :many
+SELECT * FROM ebook_notes WHERE ebook_id = $1 AND user_id = $2 ORDER BY created_at DESC;
+
+-- name: UpdateEbookNote :one
+UPDATE media_notes SET
+    content = $2,
+    position = $3,
+    updated_at = NOW()
+WHERE id = $1
+RETURNING *;
+
+-- name: DeleteEbookNote :exec
+DELETE FROM media_notes WHERE id = $1;
+
+-- Backward compatibility - Ebook Highlights queries (using views)
+-- name: CreateEbookHighlight :one
+INSERT INTO media_highlights (media_item_id, user_id, selection_text, start_position, end_position, color, note_id)
+VALUES ($1, $2, $3, $4, $5, $6, $7)
+RETURNING *;
+
+-- name: GetEbookHighlight :one
+SELECT * FROM ebook_highlights WHERE id = $1;
+
+-- name: GetEbookHighlights :many
+SELECT * FROM ebook_highlights WHERE ebook_id = $1 AND user_id = $2 ORDER BY created_at DESC;
+
+-- name: UpdateEbookHighlight :one
+UPDATE media_highlights SET
+    selection_text = $2,
+    start_position = $3,
+    end_position = $4,
+    color = $5,
+    note_id = $6,
+    updated_at = NOW()
+WHERE id = $1
+RETURNING *;
+
+-- name: DeleteEbookHighlight :exec
+DELETE FROM media_highlights WHERE id = $1;