Speed up Godot terminal rendering and fix frame pacing

[nicodes]

Honeyvale playback spends about 32 ms resizing every native-resolution frame, then waits another full 16.7 ms after rendering finishes. That makes its fixed-step simulation visibly slow.

Render near terminal resolution with Godot canvas-item scaling while preserving authored logical coordinates and game state, use bilinear final conversion, disable Nagle buffering, and count rendering/transfer time inside the 60 Hz player budget. TERMCADE_GODOT_FULL_RES=1 preserves native render targets for resolution-sensitive games. The benchmark command reports warmed exchange mean/p95, terminal-cell conversion and available engine stage timings through bounded JSON.

Sequential Honeyvale replays on the same Linux/Mesa machine, 160 columns ×45 rows, 60 warmup/120 measured steps: exchange mean 46.764 →5.600 ms (8.35×), p95 52.376 →6.994 ms. Resize mean 32.402 →1.943 ms. These measure the pipeline and exclude startup, terminal-emulator painting and player pacing; they are not an end-user FPS guarantee.

Validation: canonical make install/check passed, including five-platform compilation, lint, race/consumer tests, native rendering, low-resolution versus authored-coordinate assertions, native-resolution override, shader/UI/3D/scene transition fixtures, watchdog cleanup, and shipping archive benchmark/replay/PNG/PTY checks. Optimized Honeyvale title, movement, pause/resume and inventory replay remained functional; its bag capture was inspected. The exact one-command preview launcher passed a real PTY and clean-exit check. Honeyvale tracked source is unchanged.

This branch includes the unmerged framebuffer foundation and supersedes #38. Canonical documentation and measured JSON evidence are reviewed separately in nicodes/docs. No deployment or marketplace change.

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