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.

1 files changed, 10 insertions, 2 deletions

diff --git a/crates/wayland/src/input/layers.rs b/crates/wayland/src/input/layers.rs
index b429fbb..4450013 100644
--- a/crates/wayland/src/input/layers.rs
+++ b/crates/wayland/src/input/layers.rs
@@ -142,7 +142,7 @@ pub(super) fn background_layer_surface_under(state: &CompState, pos: Point<f64,
 /// respecting every edge here is what every mainstream desktop's own
 /// maximize convention already does. Fullscreen is unaffected - it never
 /// called this function, and still doesn't.
-pub(crate) fn maximize_geometry_for(output: &Output, full: srdwm_core::Rect) -> srdwm_core::Rect {
+pub(crate) fn maximize_geometry_for(output: &Output, full: srdwm_core::Rect, covers_dock: bool) -> srdwm_core::Rect {
     let mut rect = full;
     // `exclusive_zone`/`margin` are logical (a layer-shell client reports
     // its own reservation the same way every other layer-shell geometry
@@ -162,7 +162,15 @@ pub(crate) fn maximize_geometry_for(output: &Output, full: srdwm_core::Rect) ->
             rect.y += shrink;
             rect.height = rect.height.saturating_sub(shrink as u32);
         }
-        if data.anchor.contains(Anchor::BOTTOM) && !data.anchor.contains(Anchor::TOP) {
+        // A bottom-anchored zone (a dock) is deliberately NOT subtracted
+        // when `covers_dock` is set: maximize runs to the bottom of the
+        // screen and the dock floats over it. Asked for directly - "not
+        // sure why it doesn't go all the way down past where dock would
+        // be" - and it matches the common dock convention (macOS, and any
+        // auto-hiding dock), where the dock overlays a maximized window
+        // rather than permanently shortening it. Top/left/right zones are
+        // still honoured, so a maximized window never hides the bar.
+        if data.anchor.contains(Anchor::BOTTOM) && !data.anchor.contains(Anchor::TOP) && !covers_dock {
             let shrink = scaled(data.margin.bottom);
             rect.height = rect.height.saturating_sub(shrink as u32);
         }