nx_gx1c_canvas_gate.nx

nx_gx1c_canvas_gate.nx -- Gx-1c (seq103 EAT-BY-BUILD): <canvas> = a FIRST-CLASS sourceless render surface in the LIVE Nishi-Browser + the PER-FRAME loop = the sovereign GAME SUBSTRATE. A fetched page DECLARES <canvas>; br_layout gives it a real CSS-sized box in flow (page.bcanvas + br_find_canvas); the game loop then drives frames: update world state (yaw) -> render the REAL nx_swgpu mesh pipeline (sg_humanoid + sg_project + sg_render -- the seq103 DRY fold, NO inline rasterizer in this gate) -> point page.bimg at the fresh buffer -> the browser repaints the whole page. Frame time MEASURED (mono clock, envelope declared). Neg-control: a page WITHOUT <canvas> finds none. license_tier: ORIGINAL expect_exit: 0