[Accessibility] Rebuild native Enter-key submission as a bounded App change #756

User outcome

Keyboard and assistive-technology users can submit project and connection creation from the focused input with Enter, while search forms prevent navigation without changing live filtering.

Supersedes

PR #696 contains the correct interaction direction but its current branch carries a full-file formatting rewrite, unrelated sanitizeCssClass hardening, direct undici, dependency downgrades, and a regenerated lockfile. Rebuild from the latest main; do not merge the aggregate diff.

Bounded implementation

• Wrap the editor project input/action pair in a semantic form.
• Wrap the connection name/DSN/action group in a semantic form.
• Wrap the project-list inline creator in a semantic form.
• Give each creation action type="submit"; remove duplicate click dispatch.
• Use one shared submit path per action and preserve existing async re-entry guards.
• Wrap diagram and canvas search controls in role="search" forms whose submit handler only prevents navigation.
• Preserve native validation, current labels, password handling, live filtering, security boundaries, and visual layout.
• Do not change status-class sanitization, polling, DSN policy, exports, dependencies, package manager, or unrelated formatting.

Regression contract

• whitespace-only project names do not submit;
• valid editor and project-list names submit exactly once on Enter;
• invalid DSNs remain rejected and never call the API;
• a valid connection submits exactly once on Enter and clears the secret field through the existing handler;
• repeated submission while an async request is active remains blocked;
• diagram and canvas search Enter events prevent navigation and preserve the current filtered results;
• button click remains a single submission path;
• full typecheck, production statement/branch coverage 100%, build, CI, Security Scan, Semgrep, CodeRabbit, OpenCode, and independent current-head approval.

Documentation

Update CHANGELOG.md and add a focused doctoring entry describing native form submission, async re-entry protection, and search-form behavior. Keep APA 7th references to the WHATWG HTML form submission model and WCAG 2.2 keyboard operability guidance.