feat(api): Add stage field to dispensary PUT endpoint

Allows updating dispensary stage via API for better data management.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/src/routes/dispensaries.ts

@@ -321,6 +321,7 @@ router.put('/:id', async (req, res) => {
       status,
       country,
       slug,
+      stage,
     } = req.body;
 
     // Validate menu_type if provided
@@ -364,8 +365,9 @@ router.put('/:id', async (req, res) => {
         status = COALESCE($29, status),
         country = COALESCE($30, country),
         slug = COALESCE($31, slug),
+        stage = COALESCE($32, stage),
         updated_at = CURRENT_TIMESTAMP
-      WHERE id = $32
+      WHERE id = $33
       RETURNING *
     `, [
       name,
@@ -399,6 +401,7 @@ router.put('/:id', async (req, res) => {
       status,
       country,
       slug,
+      stage,
       id
     ]);