Reset all share modal fields after creating a link

Create only cleared the label; scope type, user email, date range, and
expiry carried over, so the next link silently inherited the previous
link's scope. Extracted openShareModal's reset logic into
_resetShareForm() and call it after every successful create.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -9,6 +9,10 @@ Version numbers follow [Semantic Versioning](https://semver.org/spec/v2.0.0.html
 
 ## [Unreleased]
 
+### Fixed
+
+- **Share modal kept stale input after creating a link** — clicking "Create" only cleared the label field; scope type, user email, date range, and expiry kept their values, so the next link silently inherited the previous link's scope settings. The form-reset logic from `openShareModal()` is now a shared `_resetShareForm()` helper called after every successful create (the generated link row stays visible for copying).
+
 ---
 
 ## [1.7.3] — 2026-06-10