[CanReader]

• Restores the shadow map to 3072² over a 128 m half-extent. Commit 1374654, a settings-panel change, had also set it to 1072² over 256 m (0.48 m per texel), which washed most shadows out. Trees cast clear shadows again.
• Pins Engine to the merge of SleakEngine#229: the SSAO occlusion test is no longer inverted (SSAO is still off in SleakCraft's config), and the custom-format pipeline cache now resets when the GBuffer pass begins.

Checked with deterministic Vulkan captures of seed 4242 (spawn, lake, forest and hill views) and a --bench-postfx --validate run with no validation messages.