chore(release): v0.16.1

CHANGELOG.md

@@ -7,6 +7,24 @@ change type. Preview the next one with `ludic dev release --dry-run`.
 A released section may carry a hand-written summary paragraph above its groups
 (v0.2.0 has one); the generated bullets below it are not edited by hand.
 
+## v0.16.1 — 2026-09-15
+
+### Features
+
+- **HDR calibration, and two HDR fixes** — the HDR10 picture follows the player's display instead of one fixed curve.
+
+  - **`r3d_hdr_calibrate(peak, paper, black)`** — nits as float bits: the brightest the display shows (100-10000),
+    where the picture's and the interface's white sit (80-1000, never above the peak) and how far the darkest shade is
+    lifted (0-5, fading out by paper white). The tonemap's and the overlay's HDR10 variants read them, and the display's
+    HDR metadata is sent again with the new peak. The defaults are the old constants: 1000, 200 and 0.
+  - **`ov_hdr_nits(nits)` / `ov_hdr_paper()`** — what the overlay draws next is at that many nits on an HDR10 frame,
+    for a calibration screen's test patches; it closes the batch so far. No effect on an SDR frame.
+  - **Fixed: a crash toggling HDR on the Vulkan renderer.** `gpu_caps_probe()` made and destroyed a second Vulkan
+    instance under NVIDIA Streamline's interposer; the next swapchain rebuild then called through a pointer that
+    instance had left behind, at address 0. With the Vulkan renderer running, the probe asks its instance instead.
+  - **Fixed: yellow read as red in HDR.** The overlay drew sRGB values straight into the HDR10 swapchain (it now has an
+    HDR10 variant, chosen while `gpu_hdr_active()`), and the tonemap extended highlights per channel, which boosted a
+    bright yellow's red far more than its green; it now brightens the graded colour by one factor.
 ## v0.16.0 — 2026-09-15
 
 ### Features