0.2.27-0.2.32: LP portal polish, brand palette, default investor logins

Cumulative checkpoint since 0.2.26:
- 0.2.27/28: entity valuation-history table; investor gain/loss = NAV +
  distributions vs paid-in
- 0.2.29: Reset Fund Partners (endpoint, Partners-tab button, CLI, action)
- 0.2.30: "Current Capital Balance" label, %-only gain/loss
- 0.2.31: Management Entities rename, Carry Vehicle type, chart
  distributions-line gate
- 0.2.32: LP-facing polish pass
  * Ten31 brand palette from the logo (navy/mint); orange retired
  * portfolio summary card across funds; gain labeled "net of paid-in"
  * whole-dollar headline figures; "History · N quarters" toggle
  * documents grouped by year with a "New" badge (users.docs_seen_at)
  * eNAV-created members start on default password with login enabled;
    enable-investor-logins CLI + StartOS action for existing accounts
  * password minimum raised to 8 chars; login help line (Portal@ten31.xyz)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/ten31portal/routers/entity_router.py

@@ -148,6 +148,26 @@ def list_partners(
     return result
 
 
+@router.delete("/{entity_id}/partners")
+def clear_partners(
+    entity_id: int,
+    user: User = Depends(require_writer),
+    session: Session = Depends(get_session),
+) -> dict[str, int]:
+    """Remove all partners from this fund — deletes its capital-account statements and the
+    investors' access grants, but keeps the investor accounts (they belong to other funds).
+    For undoing a wrong members import. Holdings/NAV are not affected."""
+    # Local import avoids a module-load cycle (capital_import_router imports import_router).
+    from ten31portal.routers.capital_import_router import reset_entity_partners
+
+    if session.get(Entity, entity_id) is None:
+        raise HTTPException(status_code=404, detail="Entity not found")
+    res = reset_entity_partners(entity_id, session)
+    record_audit(session, user.id, "clear_partners", "entity", entity_id, res)
+    session.commit()
+    return res
+
+
 @router.get("")
 def list_entities(
     user: User = Depends(get_current_user),