set up for deployment

backend/scripts/archive/migration_add_versions.sql

@@ -0,0 +1,38 @@
+-- Migration: Add document version history support
+-- Run: psql -U postgres collaboration < backend/scripts/migration_add_versions.sql
+
+CREATE TABLE IF NOT EXISTS document_versions (
+    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
+    document_id UUID NOT NULL REFERENCES documents(id) ON DELETE CASCADE,
+    yjs_snapshot BYTEA NOT NULL,
+    text_preview TEXT,
+    version_number INTEGER NOT NULL,
+    created_by UUID REFERENCES users(id) ON DELETE SET NULL,
+    version_label TEXT,
+    is_auto_generated BOOLEAN DEFAULT true,
+    created_at TIMESTAMPTZ DEFAULT NOW(),
+    
+    CONSTRAINT unique_document_version UNIQUE(document_id, version_number)
+);
+
+CREATE INDEX idx_document_versions_document_id ON document_versions(document_id, created_at DESC);
+CREATE INDEX idx_document_versions_created_by ON document_versions(created_by);
+
+-- Add version tracking to documents table
+ALTER TABLE documents ADD COLUMN IF NOT EXISTS version_count INTEGER DEFAULT 0;
+ALTER TABLE documents ADD COLUMN IF NOT EXISTS last_snapshot_at TIMESTAMPTZ;
+
+-- Function to get next version number
+CREATE OR REPLACE FUNCTION get_next_version_number(p_document_id UUID)
+RETURNS INTEGER AS $$
+DECLARE
+    next_version INTEGER;
+BEGIN
+    SELECT COALESCE(MAX(version_number), 0) + 1
+    INTO next_version
+    FROM document_versions
+    WHERE document_id = p_document_id;
+    
+    RETURN next_version;
+END;
+$$ LANGUAGE plpgsql;