Phase 16: Card Catalog, Settings/Profile, Squad Builder tabs

Card Catalog — full card database browser using GET /cards with client-
side filters (name, position, rarity, nation, league, club, OVR range),
pagination in 80-card chunks, "Owned" green overlay/badge for cards
already in the collection (cross-referenced via GET /collection).

Settings/Profile — profile card with username, level, XP progress bar;
editable game settings (default match difficulty, preferred formation)
via GET/PUT /settings; confirmation flash on save.

Squad Builder — Squad tab gains a Build/View toggle. Build mode shows
11 starter slots (labelled by position for the selected formation) plus
7 bench slots; clicking any slot opens an inline search-picker filtered
to unused collection cards; GK slot highlighted; filled slots show
player name, OVR, and position with a one-click clear button; Save
Squad POSTs the full squad to Core (validates 11 starters required) then
switches back to View mode and refreshes the chemistry display.

Formations supported: 4-4-2, 4-3-3, 4-2-3-1, 4-1-2-1-2, 3-5-2, 5-3-2.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/proxy_test.rs

@@ -248,6 +248,8 @@ async fn test_dashboard_contains_key_sections() {
     assert!(html.contains("tab-store"), "pack store tab missing");
     assert!(html.contains("tab-sbc"), "sbc tab missing");
     assert!(html.contains("tab-statistics"), "statistics tab missing");
+    assert!(html.contains("tab-catalog"), "card catalog tab missing");
+    assert!(html.contains("tab-settings"), "settings tab missing");
     assert!(html.contains("tab-notifications"), "notifications tab missing");
 }