feat(client): interests tab + pipeline summary panel + list-row counts

Promotes interests from a stub tab to a first-class surface on the client
detail page, and surfaces pipeline activity in two more places:

UI:
  - New ClientInterestsTab (475 lines) — table of every active interest
    for the client with stage-stepper visualization, lead category, source,
    last-activity timestamp, and a drawer-on-tap row preview.
  - New OverviewTab pipeline-summary panel above the existing 2-column
    layout, rendering ClientPipelineSummary (already on this branch) in
    its panel variant. Reps see the live pipeline at a glance without
    leaving Overview.
  - Removes "Preferred Language" inline field from the Overview tab and
    the create form — unused, and the field added noise without driving
    any downstream behavior.
  - Tab order: Overview / Interests / Yachts / Companies / ... (Interests
    moves up from the back of the list, where it was a stub anyway).

Data:
  - listClients now returns interestCount + latestInterest{stage, mooring}
    per row, joined from interests + berths in two parallel queries.
    ClientRow type updated to surface them; Client list views can now
    render "3 interests · last on D-02 (EOI Signed)" without a per-row
    fetch.
  - Contact rows in client detail now expose valueE164 + valueCountry to
    the UI (already returned by the API; just wasn't typed through the
    detail-page contract).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/clients/client-columns.tsx

@@ -25,6 +25,8 @@ export interface ClientRow {
   createdAt: string;
   yachtCount?: number;
   companyCount?: number;
+  interestCount?: number;
+  latestInterest?: { stage: string; mooringNumber: string | null } | null;
   contacts?: Array<{ channel: string; value: string; isPrimary: boolean }>;
   tags?: Array<{ id: string; name: string; color: string }>;
 }