First-run onboarding: contextual coach-marks + How-to-Play card + dev replay toggle

Teaches the deep, interlocking loop — especially the inverted win condition
(you win by CLEARING EXPEDITIONS, not by surviving base sieges; DR-042/DR-043).

- OnboardingSystem: client-only observe-only PresentationSystemGroup overlay
  (own UIDocument @ sortingOrder 60), soft-gated 10-beat coach-mark sequence
  with a world-space ▶ pointer; never mutates sim / never destroys a ghost.
- OnboardingStepMath: pure, unit-tested step machine (snapshot + IsSatisfied +
  scheme-aware prompts + pointer kinds + persisted-mask helpers).
- HowToPlayPanel: tabbed reference card (Controls / The Loop / Build / Threats /
  Win-Lose), reachable from the main menu and the pause overlay.
- Per-client client-local state in GameSettings (TutorialHints + OnboardingMask
  bitmask, additive) — a Join client keeps its own; a host save-wipe never
  re-teaches. Settings toggle + menu "Replay Tutorial".
- Dev "Force Each Launch" toggle (GameSettings.ForceOnboardingEachLaunch):
  SettingsService.Boot wipes the mask + forces hints on in-memory every launch
  so the tutorial always replays fresh.
- HudSystem suppresses its own location hint while onboarding is active
  (single prompt voice), via OnboardingState + [UpdateAfter(OnboardingSystem)].

Validated green: 20/20 EditMode; Play smoke confirmed overlay render, clean
U+25B6 pointer glyph, no system sort-cycle, and the force-wipe end-to-end.

Docs: DR-043 + session log; reusable lesson archived in the build-gotchas note.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Assets/_Project/Scripts/Client/UI/SettingsScreen.cs

@@ -59,6 +59,19 @@ namespace ProjectM.Client
             card.Add(VolumeRow("Music", working.Music, v => { working.Music = v; GameVolume.Music = v; }));
             card.Add(VolumeRow("SFX", working.Sfx, v => { working.Sfx = v; GameVolume.Sfx = v; }));
 
+            // ---------------- Onboarding ----------------
+            card.Add(MenuUi.Caption("— ONBOARDING —"));
+            string[] onoff = { "Off", "On" };
+            card.Add(CycleRow("Tutorial Hints",
+                () => onoff[Mathf.Clamp(working.TutorialHints, 0, 1)],
+                dir => working.TutorialHints = Wrap(working.TutorialHints + dir, 2)));
+
+            // DEV: forces the first-run coach-marks to replay fresh on every launch (wipes the completed-step mask at
+            // each boot — see SettingsService.Boot). Off = normal once-only first-run behaviour.
+            card.Add(CycleRow("Force Each Launch (Dev)",
+                () => onoff[Mathf.Clamp(working.ForceOnboardingEachLaunch, 0, 1)],
+                dir => working.ForceOnboardingEachLaunch = Wrap(working.ForceOnboardingEachLaunch + dir, 2)));
+
             // ---------------- Buttons ----------------
             var apply = MenuUi.Button("Apply", () => SettingsService.SaveAndApply(working));
             apply.style.backgroundColor = new Color(0.12f, 0.30f, 0.22f, 1f);