Convert British spellings to American across the repo

colour -> color, behaviour -> behavior, centre -> center, favourite ->
favorite, and about twenty other pairs, applied consistently across
comments, docs, error/UI copy, and a handful of QML identifiers that
used the British spelling as their actual name: SystemSettings'
serialiseValue/serialiseTable/normaliseGradient, Displays'
normaliseModes, Wallpaper's normalisePolicy, SettingsBackup's
serialiseHomeState, DateTime's ntpSynchronised property, Clipboard's
_normalise helper, and ShortcutCapture's cancelled signal (with its
onCancelled handler in ShortcutsPage.qml). Every call site and the two
tests that assert on the literal source text (settings-ownership and
settings-backup-live contracts) were updated in lockstep.

Left untouched: config/dot/espanso/match/packages/misspell-en/ is a
vendored third-party autocorrect dictionary -- its entries are typo
corrections, not our prose, and rewriting them would fight the
package's own purpose (and any future re-sync from upstream).

The already-American `favorites` property (Home page pinned
accessories) was never actually misspelled -- only nearby comments and
error strings said "favourites" -- so no data migration was needed
there.

Claude-Session: https://claude.ai/code/session_01E6TJUAh41HaP25MVHWkhRZ

config/dot/hypr/keybinds.lua

@@ -118,7 +118,7 @@ bind(mod .. " + SHIFT + F", hl.dsp.exec_cmd(qs("focus", "reveal")), { descriptio
 -- which Hyprland has no equivalent for.
 bind(mod .. " + grave", hl.dsp.exec_cmd(qs("overview", "toggle")), { description = "Overview" })
 
--- Notification centre.
+-- Notification center.
 bind(mod .. " + B", hl.dsp.exec_cmd(qs("notifications", "toggle")), { description = "Notifications" })
 
 -- Screenshot / screen record. One key, then pick screen / window / region and
@@ -133,8 +133,8 @@ bind("ALT + Print", hl.dsp.exec_cmd(qs("capture", "windowNow")), { description =
 bind(mod .. " + SHIFT + S", hl.dsp.exec_cmd(qs("screen-intelligence", "open")),
     { description = "Screen Intelligence" })
 
--- Colour picker: copies the hex under the cursor to the clipboard.
-bind(mod .. " + SHIFT + P", hl.dsp.exec_cmd("hyprpicker -a -f hex"), { description = "Colour picker" })
+-- Color picker: copies the hex under the cursor to the clipboard.
+bind(mod .. " + SHIFT + P", hl.dsp.exec_cmd("hyprpicker -a -f hex"), { description = "Color picker" })
 
 -- ── Window management ───────────────────────────────────────────────────────
 bind(mod .. " + Q", hl.dsp.window.close(), { description = "Close window" })
@@ -182,7 +182,7 @@ bind(mod .. " + CTRL + L", hl.dsp.window.swap({ direction = "r" }), { descriptio
 --
 -- Forge resized one named edge at a time. Hyprland resizes the active window
 -- along an axis and lets the layout decide which edge actually moves, so the
--- eight Forge keys collapse onto four behaviours. The pairing is kept
+-- eight Forge keys collapse onto four behaviors. The pairing is kept
 -- consistent with the original: Y/B/O/M are horizontal, I/P/U/N are vertical,
 -- and "increase" always grows while "decrease" always shrinks.
 local step = 60
@@ -192,7 +192,7 @@ bind(mod .. " + SHIFT + B", hl.dsp.window.resize({ x = -step, y = 0, relative =
 bind(mod .. " + SHIFT + M", hl.dsp.window.resize({ x = -step, y = 0, relative = true }), { repeating = true, description = "Narrower" })
 bind(mod .. " + SHIFT + I", hl.dsp.window.resize({ x = 0, y = step, relative = true }), { repeating = true, description = "Taller" })
 bind(mod .. " + SHIFT + U", hl.dsp.window.resize({ x = 0, y = step, relative = true }), { repeating = true, description = "Taller" })
--- SUPER+SHIFT+P was double-bound with the colour picker above; moved to
+-- SUPER+SHIFT+P was double-bound with the color picker above; moved to
 -- Comma, which continues the bottom-row cluster (B/M/N) this axis already
 -- uses rather than landing on an arbitrary free key.
 bind(mod .. " + SHIFT + Comma", hl.dsp.window.resize({ x = 0, y = -step, relative = true }), { repeating = true, description = "Shorter" })
@@ -227,7 +227,7 @@ bind(mod .. " + mouse:273", hl.dsp.window.resize(), { mouse = true, description
 -- moving right past the last workspace creates a new one, and moving left from
 -- the first clamps instead of wrapping.
 
--- Behaviour for the relative/cyclic binds below. These are Hyprland's own
+-- Behavior for the relative/cyclic binds below. These are Hyprland's own
 -- `binds:` options -- not part of general/dwindle -- and have no other home
 -- in the config, so they are read here rather than in looks.lua.
 hl.config({
@@ -259,18 +259,18 @@ end
 bind(mod .. " + mouse_down", hl.dsp.focus({ workspace = "+1" }), { description = "Workspace right" })
 bind(mod .. " + mouse_up", hl.dsp.focus({ workspace = "-1" }), { description = "Workspace left" })
 
--- Minimise, as far as Hyprland has one.
+-- Minimize, as far as Hyprland has one.
 --
--- Hyprland has no minimise: it receives the request (the binary has
+-- Hyprland has no minimize: it receives the request (the binary has
 -- setSetMinimized handlers for xdg, XWayland and foreign-toplevel) but exposes
 -- no dispatcher, no config option and not even an event to hook, so titlebar
--- minimise buttons are inert and cannot be made to work. A tiling WM has no
+-- minimize buttons are inert and cannot be made to work. A tiling WM has no
 -- iconified state and no taskbar to restore from.
 --
 -- The scratchpad is the honest equivalent: the window goes away, and the same
 -- key brings it back. Bound to X to match the muscle memory it replaces.
-bind(mod .. " + X", hl.dsp.workspace.toggle_special("scratch"), { description = "Toggle scratchpad (restore minimised)" })
-bind(mod .. " + SHIFT + X", hl.dsp.window.move({ workspace = "special:scratch" }), { description = "Minimise to scratchpad" })
+bind(mod .. " + X", hl.dsp.workspace.toggle_special("scratch"), { description = "Toggle scratchpad (restore minimized)" })
+bind(mod .. " + SHIFT + X", hl.dsp.window.move({ workspace = "special:scratch" }), { description = "Minimize to scratchpad" })
 
 -- ── Session ─────────────────────────────────────────────────────────────────
 -- GNOME's lock was SUPER+L, which is "focus right" here, so lock moves to