Capture omarchy-air's customizations as a per-host overlay

hosts/<hostname>/{config,system}/ now overlays the shared trees. install.sh
installs a host file in place of the shared copy at the same path, and
capture.sh pulls back into whichever copy the host installs from. That keeps
hardware-specific files off the wrong machine: the HP's EDID-named monitors.lua
and its fnmode=2 would otherwise land on the Air.

capture.sh refreshes the shared trees only on omarchy-laptop, where they were
captured, or when CAPTURE_SHARED=1 is set. On the Air, a plain run copied its
stock terminal, hypr and shell files over every one of the HP's customizations.

air's overlay holds monitors.lua (1.33333 scale and GDK_SCALE=1 for the
2560x1664 panel), input.lua (stock settings plus the inert-accel measurements),
herdr onboarding=false, git identity and credential helpers (no secrets),
mimeapps.list, and the Asahi installer's hid_apple fnmode=1 and show_notch=1.
bindings.lua is not overlaid because the shared one is a strict superset.
hosts/omarchy-air/README.md records what was left out on purpose and why, and
warns that the shared packages.txt is x86-specific.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KKPyqMc7MGKyBLKVdeDejp

hosts/omarchy-air/config/hypr/input.lua

@@ -0,0 +1,83 @@
+-- Keep only your personal input overrides here. Uncommented settings below
+-- replace Omarchy's defaults.
+
+-- Keyboard layout and options.
+-- See https://wiki.hypr.land/Configuring/Basics/Variables/#input
+-- hl.config({
+--   input = {
+--     -- Use multiple keyboard layouts and switch between them with Left Alt + Right Alt.
+--     kb_layout = "us,dk,eu",
+--     kb_options = "compose:caps,shift:both_capslock_cancel,grp:alts_toggle",
+--
+--     -- Use a specific keyboard variant if needed (e.g. intl for international keyboards).
+--     kb_variant = "intl",
+--
+--     -- Change speed of keyboard repeat.
+--     repeat_rate = 40,
+--     repeat_delay = 250,
+--
+--     -- Start with numlock on by default.
+--     numlock_by_default = true,
+--
+--     -- Increase sensitivity for mouse/trackpad (default: 0).
+--     sensitivity = 0.35,
+--
+--     -- Turn off mouse acceleration (default: adaptive).
+--     accel_profile = "flat",
+--
+--     touchpad = {
+--       -- Use traditional (non-inverse) scrolling.
+--       natural_scroll = false,
+--
+--       -- Re-enable tap-to-click (one-finger tap = left, two-finger = right).
+--       tap_to_click = true,
+--
+--       -- Use two-finger clicks for right-click instead of lower-right corner.
+--       clickfinger_behavior = true,
+--
+--       -- Control the speed of your scrolling.
+--       scroll_factor = 0.4,
+--
+--       -- Enable the touchpad while typing.
+--       disable_while_typing = false,
+--
+--       -- Left-click-and-drag with three fingers.
+--       drag_3fg = 1,
+--     },
+--   },
+-- })
+
+-- App-specific touchpad scroll speeds.
+-- o.window("(Alacritty|kitty|foot)", { scroll_touchpad = 1.5 })
+-- o.window("com.mitchellh.ghostty", { scroll_touchpad = 0.2 })
+
+-- Enable touchpad gestures for changing workspaces.
+-- See https://wiki.hypr.land/Configuring/Advanced-and-Cool/Gestures/
+-- hl.gesture({ fingers = 3, direction = "horizontal", action = "workspace" })
+
+-- Enable touchpad gestures for moving focus (helpful on scrolling layout).
+-- hl.gesture({ fingers = 3, direction = "left", action = function() hl.dispatch(hl.dsp.focus({ direction = "l" })) end })
+-- hl.gesture({ fingers = 3, direction = "right", action = function() hl.dispatch(hl.dsp.focus({ direction = "r" })) end })
+
+-- lan-mouse (handoff) virtual pointer: DO NOT add sensitivity/accel_profile rules here.
+--
+-- Tried and measured as INERT on 2026-10-10. `hl.device({name="unknown-device", ...})` does
+-- match the device (proven by toggling scroll_factor and watching hyprctl report it), but
+-- `sensitivity` and `accel_profile` are libinput pointer-acceleration settings and a
+-- wlr-virtual-pointer is not a libinput device, so they have nothing to act on. Measured
+-- travel with `lan-mouse test-emulation` + hyprctl cursorpos was 398x198px at sensitivity 0
+-- AND at -0.9 -- identical, and exactly 1:1 with the raw deltas. Both machines measure the
+-- same 398x198, so neither end scales.
+--
+-- Corollary: global `accel_profile = "flat"` would also be a no-op for the virtual pointer
+-- while permanently changing how the real trackpad feels. Pure loss -- do not do it.
+-- The magnitude of forwarded motion originates on the SENDING machine's trackpad.
+--
+-- ROOT CAUSE FOUND 2026-10-10: lan-mouse 0.11.0 forwards UNACCELERATED deltas.
+-- input-capture/src/layer_shell.rs:887 destructures the relative-pointer event as
+-- `dx_unaccel: dx, dy_unaccel: dy, ..` -- the `..` throws away the accelerated dx/dy that the
+-- same event carries. So the accel curve is stripped at the SENDER and nothing replaces it at
+-- the receiver. Consequence: sensitivity/accel_profile are inert for forwarded motion on BOTH
+-- ends, so "sync the sensitivity between the laptops" is impossible by configuration.
+-- The only fix is a source patch to use the accelerated dx/dy.
+-- See memory: lan-mouse-forwards-unaccelerated-deltas.md