fix(encode): unwind Vulkan Video open failure instead of leaking every prior object

VulkanVideoEncoder::open_inner creates ~20 Vulkan objects across ~15
fallible steps, but all cleanup lived in the encoder's Drop — which only
runs once the value exists at the final Ok(Self). Any earlier ?/bail!
leaked everything built so far (a VkDevice + GPU memory per retried
open, and this backend is the default encode path on AMD/Intel Linux
hosts where open can fail transiently).

Factor the entire teardown sequence — unchanged — into a VkTeardown
guard whose Drop destroys any prefix of the build (vkDestroy*/vkFree*
are defined no-ops on VK_NULL_HANDLE): open_inner mirrors each object
into the guard as it is created and disarms it only at Ok(Self); the
encoder's own Drop rebuilds one from its fields, so both paths share
one sequence and cannot drift. make_frame now builds in place into a
guard-parked null Frame so a mid-build failure unwinds its partial
handles too, and make_video_image / vk_util::make_plain_image (also
used by the PyroWave backend) / build_parameters_h265 no longer leak
their own partially-created objects on failure.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/pf-encode/src/enc/linux/vk_util.rs

@@ -183,7 +183,8 @@ pub(crate) unsafe fn make_plain_image(
         None,
     )?;
     let req = device.get_image_memory_requirements(img);
-    let mem = device.allocate_memory(
+    // Unwind on failure: callers (the encoders' open paths) only ever see the completed triple.
+    let mem = match device.allocate_memory(
         &vk::MemoryAllocateInfo::default()
             .allocation_size(req.size)
             .memory_type_index(find_mem(
@@ -192,8 +193,24 @@ pub(crate) unsafe fn make_plain_image(
                 vk::MemoryPropertyFlags::DEVICE_LOCAL,
             )),
         None,
-    )?;
-    device.bind_image_memory(img, mem, 0)?;
-    let view = make_view(device, img, fmt, 0)?;
-    Ok((img, mem, view))
+    ) {
+        Ok(m) => m,
+        Err(e) => {
+            device.destroy_image(img, None);
+            return Err(e.into());
+        }
+    };
+    if let Err(e) = device.bind_image_memory(img, mem, 0) {
+        device.destroy_image(img, None);
+        device.free_memory(mem, None);
+        return Err(e.into());
+    }
+    match make_view(device, img, fmt, 0) {
+        Ok(view) => Ok((img, mem, view)),
+        Err(e) => {
+            device.destroy_image(img, None);
+            device.free_memory(mem, None);
+            Err(e)
+        }
+    }
 }