Add headless-primary streaming mode + off-screen window self-heal

Desktop lives on a persistent HEADLESS output that Sunshine captures; DP-1
mirrors it when present, so streaming works whether or not the physical monitor
is on. Fixes workspace/window orphaning when the monitor powers off (the old
'HEADLESS mirrors DP-1' design collapsed when DP-1 disappeared).

- bin/sunshine-headless-primary.sh: apply (idempotent topology + rescue),
  rescue (recenter off-screen floating windows), watch (self-heal on monitor
  add/remove and on windows that open off-screen).
- bin/sunshine-prestart.sh: delegates to the manager's apply.
- docs/HEADLESS-PRIMARY.md: full rationale + the ufw stale-subnet gotcha.

Not yet wired into install.sh; configured directly on JARVIS via monitors.conf
and autostart.conf (tracked in the dotfiles repo).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

bin/sunshine-prestart.sh

@@ -1,81 +1,13 @@
 #!/usr/bin/env bash
-# Runs as a systemd ExecStartPre for the Sunshine service. Two jobs:
-#   1. Make sure exactly one Hyprland headless output exists.
-#   2. Sync sunshine.conf's `output_name` to whatever the headless output is
-#      currently named — Hyprland's HEADLESS-N counter doesn't reset across
-#      session restarts, so pinning to HEADLESS-1 drifts after the first
-#      remove/create cycle.
+# Sunshine systemd ExecStartPre hook.
 #
-# Non-fatal at every step: a stale state can't worsen things by aborting here.
-
-set -uo pipefail
-
-log() { printf '[sunshine-prestart] %s\n' "$*" >&2; }
-
-CONF="$HOME/.config/sunshine/sunshine.conf"
-
-# Recover Hyprland's instance signature when the unit's env didn't propagate it.
-if [[ -z "${HYPRLAND_INSTANCE_SIGNATURE:-}" ]]; then
-  for sig in "${XDG_RUNTIME_DIR:-/run/user/$(id -u)}"/hypr/*/; do
-    [[ -d "$sig" ]] || continue
-    export HYPRLAND_INSTANCE_SIGNATURE="$(basename "$sig")"
-    break
-  done
-fi
-if [[ -z "${HYPRLAND_INSTANCE_SIGNATURE:-}" ]]; then
-  log "Hyprland not running; nothing to prepare."
-  exit 0
-fi
-
-if ! command -v hyprctl >/dev/null || ! command -v jq >/dev/null; then
-  log "hyprctl/jq missing; skipping prestart."
-  exit 0
-fi
-
-# Reduce to exactly one headless output. Hyprland's HEADLESS-N counter
-# increments on every create and never decrements, so previous failed runs
-# leave extras laying around. Remove all but the lowest-numbered one (most
-# likely to be the one with workspaces bound to it).
-mapfile -t headless_outputs < <(hyprctl monitors -j 2>/dev/null \
-  | jq -r '.[] | select(.name | startswith("HEADLESS")) | .name' \
-  | sort -V)
-existing="${headless_outputs[0]:-}"
-
-if [[ -z "$existing" ]]; then
-  log "No headless output present; creating one"
-  hyprctl output create headless >/dev/null
-  for _ in 1 2 3 4 5; do
-    existing="$(hyprctl monitors -j 2>/dev/null \
-      | jq -r '.[] | select(.name | startswith("HEADLESS")) | .name' \
-      | sort -V | head -1)"
-    [[ -n "$existing" ]] && break
-    sleep 0.1
-  done
-elif [[ ${#headless_outputs[@]} -gt 1 ]]; then
-  log "Found ${#headless_outputs[@]} headless outputs; keeping $existing, removing the rest"
-  for extra in "${headless_outputs[@]:1}"; do
-    hyprctl output remove "$extra" >/dev/null 2>&1 || true
-  done
-fi
-
-if [[ -z "$existing" ]]; then
-  log "Failed to obtain a headless output; Sunshine will start without one."
-  exit 0
-fi
-log "Headless output present: $existing"
-
-# Sync sunshine.conf's output_name. Only touch the file if it's our managed
-# variant (has the management marker) AND the line has actually drifted.
-if [[ -f "$CONF" ]] && grep -qF '# managed-by: omarchy-moonlight' "$CONF"; then
-  current="$(awk '/^output_name = / {print $3; exit}' "$CONF" 2>/dev/null || true)"
-  if [[ "$current" != "$existing" ]]; then
-    log "Updating sunshine.conf output_name: ${current:-(unset)} -> $existing"
-    if grep -q '^output_name = ' "$CONF"; then
-      sed -i "s|^output_name = .*|output_name = $existing|" "$CONF"
-    else
-      printf '\noutput_name = %s\n' "$existing" >> "$CONF"
-    fi
-  fi
-fi
-
-exit 0
+# As of 2026-07-27 this is a thin wrapper around the HEADLESS-PRIMARY manager,
+# which is the single source of truth for the monitor/headless topology:
+#   - ensures exactly one persistent HEADLESS output exists (Sunshine's capture
+#     target) BEFORE Sunshine's startup encoder probe runs,
+#   - sizes it and mirrors DP-1 onto it when the physical monitor is present,
+#   - keeps sunshine.conf's output_name in sync with the live headless name.
+#
+# Non-fatal by design (the drop-in prefixes this with '-'): if Hyprland isn't
+# reachable yet, the manager logs and returns 0 so Sunshine still starts.
+exec "$(dirname "$0")/sunshine-headless-primary.sh" apply