Fix spawn placement under the top bar, add per-window minimum sizes, and clean up maximize

Four reports after restarting into today's build, with a screenshot. The
screenshot was measured, not eyeballed: top bar y=0..29, a 4px accent border
at y=30..33, titlebar from y=34, bottom border at y=1027..1030, and 49px of
bare desktop below it.

Windows spawning too close to the top bar. A remembered position was
validated only by asking whether it landed on some monitor's full_geometry,
which includes the strip a top bar reserves, so an app whose remembered y was
small reopened with its titlebar under the bar. That is why it was
"sometimes": it depended on the stored value, and the live store holds
wezterm at y=44 and firefox at y=69 against a 30px bar. Remembered positions
are now clamped into the monitor's usable area.

Placement not surviving a logout. Window memory does persist, but five of the
eleven entries in the live store were saved with a second monitor attached,
at x >= 2000. Those points match no current monitor and were discarded
outright, falling back to a fresh cascade, so those apps appeared to remember
nothing. Such a position is now clamped onto a monitor that exists instead.

Per-window minimum sizes. One global floor is wrong in both directions.
Three sources now, in increasing precedence: the global floor, the client's
own declared minimum (xdg_toplevel.set_min_size or ICCCM hints), and a
min_width/min_height window rule overriding both. A rule wins permanently --
the backend refreshes the client's declared minimum on every decoration
redraw and must not undo a deliberate override.

Maximize, three faults in one report. A maximized window now draws no
border: its edges are the screen's edges, and the only place maximize stops
short is the bar strip, which is exactly where the measured line was.
maximize_geometry_for no longer subtracts a bottom-anchored dock's exclusive
zone, so maximize runs to the bottom of the screen and the dock floats over
it; top, left and right are still honoured.
general.maximize_covers_dock = false restores the old behaviour. With the
border gone the window sits flush under the bar instead of with an accent
line crowding it.

Verified: seven new tests on the real numbers from the live store, and
maximize geometry measured live in a nested instance (a window maximized on a
split half reports exactly that half's rect). NOT confirmed on screen: the
border removal and the dock behaviour - the nested backend has no bar or
dock to reserve a zone, and an attempt to check the border produced a failing
control, since srd set border_width only affects windows created after it.

515 tests pass, clippy clean.

2 files changed, 11 insertions, 2 deletions

diff --git a/crates/wayland/src/udev/platform.rs b/crates/wayland/src/udev/platform.rs
index 0ae65f7..ea2260e 100644
--- a/crates/wayland/src/udev/platform.rs
+++ b/crates/wayland/src/udev/platform.rs
@@ -830,7 +830,7 @@ impl Platform for UdevPlatform {
             // deliberately *not* defaulted from `usable` the way `Monitor::
             // new` alone would (see the fullscreen note below).
             let full = srdwm_core::Rect::new(head.location.x, head.location.y, head.size.0 as u32, head.size.1 as u32);
-            let maximize = crate::input::maximize_geometry_for(&head.output, full);
+            let maximize = crate::input::maximize_geometry_for(&head.output, full, wm.maximize_covers_dock);
             let name = head.output.name();
             let split = wm.monitor_split(&name);
             let parts = split.map(|s| s.parts).unwrap_or(1).max(1);
diff --git a/crates/wayland/src/udev/render.rs b/crates/wayland/src/udev/render.rs
index aa05529..3bd9a52 100644
--- a/crates/wayland/src/udev/render.rs
+++ b/crates/wayland/src/udev/render.rs
@@ -334,7 +334,16 @@ impl CompState {
                         // be_masked` degenerates to just `w.decorated` when
                         // masking can never succeed).
                         let border_curve_is_safe = w.decorated;
-                        if w.border_width > 0 {
+                        // No border on a maximized window. A maximized window's own
+                        // edges are the screen's edges, so a border has nothing to
+                        // separate it from - and where maximize *does* stop short (the
+                        // strip a top bar reserves) the border lands in that gap, drawn
+                        // as a hard line right against the bar. Reported live with a
+                        // screenshot: a 4px accent line between the bar and the window,
+                        // and none anywhere else, because the left/right/bottom strips
+                        // fall off-screen. Fullscreen is already borderless for the
+                        // same reason, via `decorated` being cleared.
+                        if w.border_width > 0 && !w.maximized {
                             let strips = decoration::border_strips(geom, w.border_width);
                             if let Some(buffer) = self.border_top_decorations.get(&id) {
                                 let (row0, rows, shift) = decoration::border_top_visible_rows(border_curve_is_safe, w.border_width, w.corner_radius);