initial seed: retrofit campaign lineage from local working trees

panvk-bifrost campaigns (r1..r4 Vulkan compositor + r5.video1 Vulkan
video decode) shipped before this repo existed; the deliverable
patches live in marfrit-packages, but the reasoning chain, phase docs,
and source-state evidence lived only in local working trees on the
development host.

This retrofit imports:
- mesa-panvk-bifrost/   — r1..r4 era phase docs (iter1..iter18)
                          (libmali stub blobs at iter18/blob/ excluded
                          — 109MB of RE artifacts replaced with a README
                          pointer)
- mesa-panvk-bifrost-video/ — sibling campaign phase docs + probe
- evidence/             — frozen .tgz source snapshots at each milestone
                          (basis for the 0005 patch diff generation)

Future iterations should branch off here from day one, so each iter is
a commit rather than a snapshot. See [[feedback-session-local-process-pins]]
for the process drift this retrofit closes.

Total: 1.9 MB across 124 files.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

mesa-panvk-bifrost/iter5/probe_vbo_ubo.vert

@@ -0,0 +1,18 @@
+#version 450
+
+// iter5 vertex shader: read pos (vec2) + color (vec3) from vertex buffer,
+// apply mat4 transform from UBO, output interpolated color to fragment.
+
+layout(location = 0) in vec2 inPos;
+layout(location = 1) in vec3 inColor;
+
+layout(set = 0, binding = 0) uniform UBO {
+    mat4 transform;
+} ubo;
+
+layout(location = 0) out vec3 vColor;
+
+void main() {
+    gl_Position = ubo.transform * vec4(inPos, 0.0, 1.0);
+    vColor = inColor;
+}