NC34 compatibility smoke test + max-version bump

[Jaggob]

appinfo/info.xml currently declares <nextcloud min-version="30" max-version="33"/>. NC34 is upcoming; when it lands we should:

1. Install NC34 on a test instance.
2. Run the plugin end-to-end: create, open, sync, trash/restore, public share, embed, templates, legacy migration.
3. Watch nextcloud.log for deprecation warnings from any OCP APIs we use.
4. Bump max-version="34" in info.xml.
5. Ship a patch release (1.1.1 or whatever's next).

Pre-emptive checks worth doing before NC34 hits

• Search OCP\ imports for anything marked @deprecated in NC33's source.
• Verify event-listener signatures still match (we hook FileCreatedFromTemplateEvent, NodeRestoredEvent, MoveToTrashEvent, AddContentSecurityPolicyEvent, LoadAdditionalScriptsEvent).
• Verify the IProviderV2 preview-provider interface is unchanged.

Acceptance

• Smoke test passes on NC34.
• max-version bumped.
• Patch release published.