Phase 19 — onboarding: hint tour + Help modal + tooltip pass

Three-agent fan-out (gdscript-refactor x3) ships the chosen Phase 19
approach: contextual hints during first session + a Help reference,
plus a sweep of hover tooltips for desktop discoverability.

- HintSystem (autoload) + HintOverlay (layer 22 top-center banner):
  7-step tour gated on player events — welcome (boot+2s), pawn select,
  build drawer open, stockpile painted, work matrix open, day_ended,
  tour_complete. Per-hint dismissals persist as Array[String] in
  GameState.settings['dismissed_hints']. Max-3 FIFO queue if hints
  chain. Reduce-motion path snaps in/out instead of tweening.
  Reset_tour() public API for the Help modal.

- HelpModal (layer 20): 5-tab static reference (Controls / Verbs /
  Priorities / Storyteller / Tips). Opens via EventBus.help_requested,
  dimmed backdrop, X/Esc/backdrop-tap dismiss. SettingsMenu gains an
  'Onboarding' section: Show-hints checkbox, Help button (emits
  help_requested), Reset hints button (calls HintSystem.reset_tour with
  has_method guard). Pre-existing 'W' keybind reference fixed to 'P'.

- Tooltip pass: tooltip_text via Strings.t on every TopBar button
  (10 buttons incl. speed shortcuts), BuildDrawer FAB, and every tool
  button in BuildDrawer (21 tools). _add_tool_btn extended with optional
  tooltip param. ~34 new tooltip.* string keys.

Contracts pre-written (Opus): EventBus.help_requested, hint_dismissed,
ui_panel_opened signals; GameState show_hints + dismissed_hints
defaults; BuildDrawer.open + WorkPriorityMatrix.open emit
ui_panel_opened so HintSystem can subscribe via one signal.

Also recorded [MED] known bug in memory.md: drag-paint with active
paint tool is eaten by camera drag-pan.

MCP runtime verified: welcome banner fires 2s after boot, dismiss
queues build_drawer hint on next ui_panel_opened, dismissed_hints
persisted as ['welcome'], HelpModal opens via help_requested with
tab switching working (Controls → Tips verified visually).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

autoload/event_bus.gd

@@ -65,6 +65,11 @@ signal request_wolf_spawn(count: int)              ## Phase 15 EventCatalog →
 signal wolf_spawned(wolves: Array)                 ## Emitted by WolfSpawner AFTER a raid wave has been instantiated; carries the spawned Wolf nodes. Audio uses this for raid-warning sting.
 signal day_ended(summary: Dictionary)              ## Emitted by Clock at dusk→night boundary; carries the end-of-day recap dict.
 
+# Phase 19 — Onboarding (hint system + help section).
+signal help_requested                              ## Settings "Help" button → opens HelpModal.
+signal hint_dismissed(hint_id: StringName)         ## Emitted by HintOverlay when player closes a hint; HintSystem persists the dismissal.
+signal ui_panel_opened(panel_id: StringName)       ## Emitted by UI panels (build_drawer, work_matrix, ...) when they become visible. HintSystem subscribes for tour gating.
+
 # Phase 18 — Alert wiring (dangling signals surfaced to AlertsLog).
 signal no_stockpile_accepts(item_type: StringName, tile: Vector2i) ## Emitted by HaulingProvider when an item needs haul but no stockpile accepts it (rate-limited per item_type).
 signal bill_blocked(recipe_label: String, reason: StringName, focus_tile: Vector2i) ## Emitted by CraftingProvider when a bill cannot proceed. reason: missing_ingredient | skill_too_low | no_workbench.