Historical rendering, focus, and input fidelity

1. REN-401Todo
   Layout is deterministic under constrained viewports and preserves focus/navigation order.→
2. REN-402Todo
   Columns, cells, whitespace preservation, line breaks, and constrained overflow follow WML semantics.→
3. REN-403Todo
   Mandatory alt behavior and supported image rendering are correct; optional spacing/alignment/size hints are explicitly claimed or deferred.→
4. REN-404Todo
   Historical keypad/softkey traversal is deterministic; optional tabindex is capability-declared and tested when enabled.→
5. REN-405Todo
   Representative WML decks replay to stable render lists, focus states, history, and emitted effects across native and WASM.→

Exit contract

Evidence required to leave this sprint

• Mandatory visual/interactive SCR behavior has golden evidence.
• Optional render hints are capability-declared.
• No rendering semantics are implemented in transport or host adapters.