feat: v2 — div+flex, YAML state, nested state, template v2

[anakod]

TelaOS v2 syntax + div/flex layout

New features

• div container — nesting, bgcolor/visible bind, CSS, padding, overflow
• Flex layout — row/column/wrap/reverse, gap, justify, align, grow
• YAML state — brightness: 50 instead of <int name="brightness" default="50"/>
• Nested state — dotted paths {player.x}, arrays {items[0]}
• Lua proxy — state.player.x = 50, state.items[1], #state.items
• Template v2 — <TableCell>body</TableCell> instead of <template id="TableCell">
• isOsV2() — os=1.0 old parser, os=2.0 new. Per-app migration.

Files changed

File	Changes
state_store.h	Arrays API (defineArray, hasArray, getArrayItem, setArrayItem) + hasPrefix
lua_engine.cpp/h	Nested proxy (pushProxy, lua_proxy_index/newindex/len)
ui_html.cpp	YAML state parser, template v2 parser, div+flex, resolve_binding
ui_types.h	Element::Div tag

Tests

TelaCI PR: Tela-CICD#1 — 62/62 green (8 new test files, 150+ checks)