Add the user-submission flow for the catalog

Lets users submit a private catalog entry (port type, cable type, device
template) for promotion to the public catalog, or suggest an edit to an
existing public entry — both go into the catalog_submissions review queue
per organized-ideas.md §3. No Admin review UI yet (next sub-phase); this
covers the submitter's side only.

- data/SubmissionRepository + SupabaseSubmissionRepository: submit,
  resubmit, withdraw, list-mine, backed by the existing catalog_submissions
  RLS policies (no schema changes needed).
- data/catalogRowMapping.ts: shared domain<->row mappers, in both
  directions, so a submission's proposed_data is always shaped like the
  underlying table row (what an eventual admin-approval would write
  directly) and can be turned back into form-editable fields for revision.
- state/submissionStore.ts: mySubmissions + submit/resubmit/withdraw, plus
  syncProposedData — called from catalogStore's updateCustom* actions so a
  submission about your own still-private entry never goes stale relative
  to it (edits from the library and from My Submissions are the same
  action and always agree).
- UI: "Submit"/"Suggest edit" wired into PortTypeManager, CableTypeManager,
  DevicePalette/DeviceTemplateEditor; new MySubmissionsModal (opened from
  TopBar, with a pending-count badge) shows status, rejection reasons, and
  lets you edit/resubmit or withdraw.
- Deliberately deferred: device_category submissions (no listing UI to
  hang a button on yet) and the normalized manufacturer catalog.

Verified: tsc -b and oxlint clean; supabase db reset + 23/23 pgTAP RLS
tests still pass (no schema changes this round); manually tested submit,
suggest-edit, edit-from-either-side sync, reject/resubmit, and withdraw.

src/components/layout/TopBar.tsx

@@ -1,17 +1,26 @@
-import { useEffect, useRef, useState } from 'react'
+import { useEffect, useMemo, useRef, useState } from 'react'
 import { downloadProjectFile, readProjectFile, ProjectImportError } from '../../data/exportImport'
 import { supabase } from '../../data/supabaseClient'
 import { useProjectStore } from '../../state/projectStore'
+import { useSubmissionStore } from '../../state/submissionStore'
+import MySubmissionsModal from '../submissions/MySubmissionsModal'
 import DiagramManagerModal from './DiagramManagerModal'
 
 export default function TopBar() {
   const project = useProjectStore((s) => s.project)
   const renameProject = useProjectStore((s) => s.renameProject)
   const importProject = useProjectStore((s) => s.importProject)
+  const mySubmissions = useSubmissionStore((s) => s.mySubmissions)
   const fileInputRef = useRef<HTMLInputElement>(null)
   const [diagramManagerOpen, setDiagramManagerOpen] = useState(false)
+  const [submissionsOpen, setSubmissionsOpen] = useState(false)
   const [username, setUsername] = useState<string | null>(null)
 
+  const pendingSubmissionCount = useMemo(
+    () => mySubmissions.filter((s) => s.status === 'pending').length,
+    [mySubmissions],
+  )
+
   // One-time fetch — nothing else in the app changes your own username after
   // CompleteProfileScreen sets it, so there's no need to keep this live.
   useEffect(() => {
@@ -60,6 +69,17 @@ export default function TopBar() {
         >
           Diagrams
         </button>
+        <button
+          onClick={() => setSubmissionsOpen(true)}
+          className="rounded px-2.5 py-1.5 text-xs text-slate-600 hover:bg-slate-100"
+        >
+          My Submissions
+          {pendingSubmissionCount > 0 && (
+            <span className="ml-1 rounded-full bg-amber-100 px-1.5 py-0.5 text-[10px] font-semibold text-amber-700">
+              {pendingSubmissionCount}
+            </span>
+          )}
+        </button>
         <button onClick={handleImportClick} className="rounded px-2.5 py-1.5 text-xs text-slate-600 hover:bg-slate-100">
           Import
         </button>
@@ -79,6 +99,7 @@ export default function TopBar() {
         </button>
       </div>
       {diagramManagerOpen && <DiagramManagerModal onClose={() => setDiagramManagerOpen(false)} />}
+      {submissionsOpen && <MySubmissionsModal onClose={() => setSubmissionsOpen(false)} />}
     </header>
   )
 }