Fix the maximize border on the path that actually runs, and three spawn faults

The maximize border was still drawn because the earlier fix landed on the
wrong branch. udev/render.rs has three border blocks: the SRDWM_GPU=1 path
at the top and two Pixman ones below. The patch replaced the first match in
the file, which is the GPU branch a real DRM session never runs. All four
sites across both backends are now gated on !maximized.

The verification had failed twice for a separate reason: winit/capture.rs
did not draw border strips at all, so a screenshot could never answer "is
there a border here" and the control passed for the wrong reason. Border
strips are now drawn into that pass as solid fills - corner rounding is not
reproduced, so a capture is not pixel-exact at the corners, but presence,
position, thickness and colour are. With that closed the test has a real
control: unmaximized gives 6 accent pixels at x=800..805, exactly the
configured border_width, and maximized gives none at the right edge or along
the top row. That proves the winit path; the Pixman path is the same change
at two more sites and is not separately confirmed on screen.

Windows spawning as squares, partly off-screen, and always on the left were
all SmartPlacement::grid. It returned size.min(cell), shrinking every window
to its grid cell whatever size it asked for; it scanned cells in reading
order and took the first free one, which is the leftmost; and nothing clamped
the result, so a window larger than its cell could hang off the edge with its
border out of view. The cell now decides only where a window goes, the scan
starts from a rotating cell, and both grid and cascade clamp into the usable
area. Four tests, one per reported symptom.

525 tests pass, clippy clean.

2 files changed, 10 insertions, 2 deletions

diff --git a/crates/wayland/src/udev/platform.rs b/crates/wayland/src/udev/platform.rs
index ea2260e..8dad7c3 100644
--- a/crates/wayland/src/udev/platform.rs
+++ b/crates/wayland/src/udev/platform.rs
@@ -268,6 +268,7 @@ impl UdevPlatform {
             rounded_content_buffers: HashMap::new(),
             border_side_buffers: HashMap::new(),
             snap_preview_buffers: Vec::new(),
+            capture_border_buffers: Vec::new(),
             color_filter_buffers: HashMap::new(),
             last_synced_size: HashMap::new(),
             provisional_size: HashSet::new(),
diff --git a/crates/wayland/src/udev/render.rs b/crates/wayland/src/udev/render.rs
index 3bd9a52..9992b2c 100644
--- a/crates/wayland/src/udev/render.rs
+++ b/crates/wayland/src/udev/render.rs
@@ -668,7 +668,14 @@ impl CompState {
                     // instead, since `custom_elements` composites earlier-
                     // pushed entries over later ones - exactly backwards
                     // from what this overlap needs.
-                    if w.border_width > 0 {
+                    // No border on a maximized window - see the matching
+                    // gate on the GPU path above. This is the Pixman path,
+                    // the one a real DRM session actually runs: the earlier
+                    // fix landed only on the GPU branch, so the border kept
+                    // being drawn on real hardware and was reported again as
+                    // "i still see the border or at least the top border
+                    // when maximized".
+                    if w.border_width > 0 && !w.maximized {
                         let strips = decoration::border_strips(frame, w.border_width);
                         // Strip 0 (top) rounded on its own two corners - see
                         // `render_border_top`'s own doc comment - so it's a
@@ -773,7 +780,7 @@ impl CompState {
                     // (unlike the bottom strip) *do* need cropping against
                     // this same top/bottom-strip overlap, a real bug this
                     // comment used to claim didn't exist here at all.
-                    if w.border_width > 0 {
+                    if w.border_width > 0 && !w.maximized {
                         let color = crate::state::effective_border_color(w.border_color, focused == Some(id), self.wm.borrow().theme.border_inactive_dim);
                         let strips = decoration::border_strips(frame, w.border_width);
                         // Strip 1 (bottom), the top strip's own mirror --