Member dashboard: drill-down tree, list view, legend, and strategy-aware referral tool

- "Your team" now covers the member's FULL leg with click-to-drill
  pyramid, breadcrumb, and a list-view toggle (mirrors the admin matrix).
- Legend under both the member tree and admin matrix explaining the
  qualified checkmark, tier badges, and downline rollup.
- "Share this position" card: while under 2/2 it's a personal recruiting
  tool — per-member QR (vendored qrcode-generator, CSP-safe), copy link,
  and a join CTA carrying the member's ID as sponsor. At 2/2 the page
  automatically retires the link and redirects sharing to the team
  rotator, so personal referrals can't undermine the moving-link
  strategy.

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

public/styles.css

@@ -114,3 +114,7 @@ a{color:inherit}.wrap{width:min(1160px,calc(100% - 32px));margin:auto}.nav{heigh
 .qr-cta small{color:var(--muted);font-weight:600}
 @media(min-width:561px){.hero-actions{align-items:center}.qr-cta{order:3;flex-basis:100%;justify-content:center;margin-top:8px}}
 @media(max-width:560px){.qr-cta{justify-content:center}}
+
+.qr-img{width:120px;height:120px;background:#fff;padding:7px;border-radius:12px;display:block;flex:0 0 auto}
+.qr-img svg,.qr-img img{width:100%;height:100%;display:block}
+img.qr-img{object-fit:contain}