Make attachment storage paths relative in database with cross-platform support (#967)

backend/internal/data/migrations/postgres/20250826000000_make_attachment_paths_relative.sql

@@ -0,0 +1,25 @@
+-- +goose Up
+-- Make attachment paths relative by removing the prefix path
+-- This migration converts absolute paths to relative paths by finding the UUID/documents pattern
+
+-- Update Unix-style paths that contain "/documents/" by extracting the part starting from the UUID
+-- The approach: find the "/documents/" substring, go back 37 characters (UUID + slash), 
+-- and extract from there to get "uuid/documents/hash"
+UPDATE attachments 
+SET path = SUBSTRING(path FROM POSITION('/documents/' IN path) - 36)
+WHERE path LIKE '%/documents/%' 
+  AND POSITION('/documents/' IN path) > 36;
+
+-- Update Windows-style paths that contain "\documents\" by extracting the part starting from the UUID
+-- Convert backslashes to forward slashes in the process for consistency
+UPDATE attachments 
+SET path = REPLACE(SUBSTRING(path FROM POSITION('\documents\' IN path) - 36), '\', '/')
+WHERE path LIKE '%\documents\%' 
+  AND POSITION('\documents\' IN path) > 36;
+
+-- For paths that already look like relative paths (start with UUID), leave them unchanged
+-- This handles cases where the migration might be run multiple times
+
+-- +goose Down
+-- Note: This down migration cannot be safely implemented because we don't know 
+-- what the original prefix paths were. This is a one-way migration.