changes

CLAUDE.md

@@ -83,6 +83,24 @@ Odoo content-hashes the compiled bundle URL (`/web/assets/<hash>/...`). When CSS
 - Local URL: http://localhost:8069
 - Test before deploying. Edit existing files — don't create unnecessary new ones.
 
+## PDF Preview — Prefer fusion_pdf_preview Over Downloads/New-Tab
+When a Python action opens an attachment, route it through `fusion_pdf_preview` instead of returning `ir.actions.act_url` with `download=true` or `target=new`. The preview dialog gives operators preview + print + download in one place and writes an audit log; non-PDF attachments fall back to the legacy download path automatically.
+
+The drop-in replacement is the new helper on `ir.attachment`:
+```python
+return att.action_fusion_preview(title='My Doc')
+# vs. the old pattern:
+# return {'type': 'ir.actions.act_url',
+#         'url':  '/web/content/%s?download=true' % att.id,
+#         'target': 'new'}
+```
+
+The helper auto-detects mimetype: PDFs go to the dialog, everything else (ZPL, CSV, XML, images) stays on download. So a callsite that today serves CSV today and a PDF tomorrow doesn't need a code change — same call, different routing.
+
+If you need to invoke the client action directly (rare — only when you don't have a recordset handy), the tag is `fusion_pdf_preview.open_attachment` and the params are `{attachment_id, title, model_name, record_ids, report_name}`. See `fusion_pdf_preview/static/src/js/open_attachment_action.js`.
+
+Existing reports (`ir.actions.report` of type `qweb-pdf`) are intercepted automatically by `fusion_pdf_preview/static/src/js/pdf_preview.js`; the helper above is for the *other* pattern — attachments opened by custom buttons.
+
 ## Supabase Knowledge Base
 Before starting unfamiliar work, check Supabase for context:
 ```bash