Add session shell and close world presentation follow-ups

Session shell
- Startup venue menu (src/game/ui/start_menu.gd): keyboard + mouse, replaces
  the live-shift boot and V as the player-facing venue path (V stays a debug bind).
- Pause overlay on Esc (src/game/ui/pause_overlay.gd): resume, restart shift,
  settings, quit to menu.
- Settings panel (src/game/ui/settings_panel.gd): mouse look sensitivity and
  HUD font scale, persisted via Save into user://settings.json and loaded on boot.
- Shift review "Run another shift" now returns to the venue menu.
- New smoke: src/test/smoke_session_shell.gd (menu -> shift -> pause -> settings
  -> menu), passes headless and windowed.

World and presentation
- Skyline backdrop restored with a transparent asset and an alpha-scissor
  unshaded material; fixes the opaque black slab from the earlier attempt and
  the unimported texture path.
- Steps and landing are a StaticBody3D with per-tread colliders, so the guard
  and NPCs walk up instead of clipping through.
- Marquee Label3D scaled up (72 -> 160) so STEP LINE reads from the sidewalk.
- Focus torus and name tag enlarged for 2-3 m readability.
- Routine traffic despawns after an idle lifetime (NpcAvatar.ephemeral), so the
  16-NPC cap no longer fills with standers; authored events stay for the shift.

Docs and tests
- PLAN.md test/CI section corrected to the custom headless runner and Gitea Actions.
- README controls table, smoke checklist, test count, and status lists refreshed.
- TODO/DONE/MEMORY updated; completed sections moved to DONE.md.
- Headless suite 77 -> 88 passing (settings round-trip, step colliders, skyline
  alpha, session-shell UI behavior, traffic lifetime).

README.md

@@ -204,6 +204,9 @@ godot --path . --script res://src/test/take_screenshot.gd
 
 # Windowed control smoke: focus ring + action wheel, saves PNGs, exits 1 on failure
 godot --path . --script res://src/test/smoke_focus_radial.gd
+
+# Session-shell smoke: menu → shift → pause → settings → menu (headless or windowed)
+godot --headless --path . --script res://src/test/smoke_session_shell.gd
 ```
 
 The unit test runner is the project's own lightweight harness (no editor plugin required) so CI can run it without the editor.
@@ -216,7 +219,9 @@ The unit test runner is the project's own lightweight harness (no editor plugin
 | Space / left click | Action wheel for the focused person |
 | A / D or ←/→ | Step through the action wheel (while it is open) |
 | Space / left click | Confirm the highlighted action (while the wheel is open) |
-| Esc / right click | Close the top panel; Esc with nothing open releases / captures the mouse |
+| Esc / right click | Close the top panel; Esc with nothing open pauses the shift (Esc again resumes) |
+| ← / → or ↑ / ↓ | Navigate the venue menu and the pause / settings panels |
+| Enter | Start the highlighted venue from the menu, or confirm in a panel |
 | 1 / 2 / 3 | Quick gestures without the wheel: raise hand, point, head shake (Level 1) |
 | Q | Polite direction (Level 1) |
 | 4 | Formal warning (Level 2) |
@@ -226,7 +231,7 @@ The unit test runner is the project's own lightweight harness (no editor plugin
 | E | Inspect access artifacts / close inspection |
 | C | Handheld wand screening (wand venues only) |
 | A / D | Allow / deny entry during inspection or wand check |
-| V | Cycle venue: Hollywood Blvd → The Joke Shop → TV Studio (restarts shift) |
+| V | Cycle venue (debug shortcut; restart via V restarts the current shift) |
 | Tab | Cycle target among nearby NPCs (aim-free alternative) |
 | G | Toggle flashlight (widens NPC perception at night) |
 | L | Lock / unlock the restricted door (thwarts forced entry) |
@@ -253,31 +258,40 @@ Implemented so far:
 - Godot 4.3 project scaffold, input map, procedural world builder
 - Venue-driven simulation core: `ShiftCoordinator`, `VenueScenario`, `EventScheduler`, `NPCController` + FSM, `AccessVerifier`, `EscalationManager`, `RadioSystem`, `IncidentRecorder`, `ReputationEvaluator`, `CrowdSystem`
 - Three authored scenarios (Hollywood Boulevard building, The Joke Shop, Late Night TV Studio) with access policies, NPC archetypes, and event pools
-- Headless unit tests: **77 passing** (access rules and venue-correct access loadout, escalation, radio cooldown/battery, NPC reaction determinism, door lock, flashlight perception, persistence round-trip, navmesh, scenario data, full-shift simulation, wand screening, responder dispatch, localization strings, focus cone and action wheel)
+- Headless unit tests: **88 passing** (access rules and venue-correct access loadout, escalation, radio cooldown/battery, NPC reaction determinism, door lock, flashlight perception, persistence round-trip, settings round-trip, navmesh, step colliders, skyline alpha, scenario data, full-shift simulation, wand screening, responder dispatch, localization strings, focus cone, action wheel, session shell)
 - Simulation extras: protester archetype, CALL_SOMEONE reaction, door lock/secure mechanic (visual indicator), flashlight with night perception bonus, LATE shift phase reaching the violent-threat event
 - First-person prototype with interaction HUD, access inspection, wand screening, radio report form (incl. emergency hold-to-confirm), dispatched responder avatars, aim-free targeting, venue cycling between all three scenarios, color-coded escalation feedback, procedural audio cues, navigation-mesh NPC paths, JSON-backed localized strings, persisted shift history, debug overlay, and shift review
 - Control pass: focus cone on NPC heads with a billboarded gold ring and name, action wheel (LMB/Space) with de-escalation-first slices, mouse-look freeze while a panel is open, acceleration-based walking, and named input actions (`action_menu`, `confirm`, `cancel`, `inspect`, `wand`)
+- Session shell: venue start menu (keyboard + mouse), Esc pause overlay (resume / restart / settings / quit to menu), settings panel with mouse-look sensitivity and HUD font scale persisted to `user://settings.json`, and "Run another shift" returning to the venue menu
+- World presentation: skyline backdrop rendered with an alpha material, walkable step and landing colliders, larger marquee text, and larger focus ring / name tag
+- Routine traffic despawns after a while at its waypoint so the crowd cap no longer fills with idle standers
 - Visual polish pass (v0.2.0): phase-based lighting (sun/sky/ambient per shift phase), street lamps with night-mode bulbs and omni lights, glowing marquee signage, crosswalk, planters and low-poly street trees, NPC height/brightness variety, denser routine traffic — day and late-night screenshot sets
 - Assets pass: authored textures in `assets/textures/` (brick facade, concrete, asphalt, awning, skyline, vignette, HUD icons, access-card art) generated by `tools/generate_textures.py`, soft sun shadows, humanoid NPC rigs with archetype props + procedural walk bob and attention head-turn, inspection artifact cards, escalation vignette, mode icons, and a body-camera overlay (REC + shift clock)
 
-Not yet implemented: body-camera replay timeline, venue selection startup menu, pause/settings shell, eye-contact and request-reason verbs, crowd rubbernecking, emergency aftermath, editor-based GUT integration, and crowd performance profiling/LOD (see `TODO.md`).
+Not yet implemented: body-camera replay timeline, eye-contact and request-reason verbs, crowd rubbernecking, emergency aftermath, editor-based GUT integration, and crowd performance profiling/LOD (see `TODO.md`).
 
 ### Smoke Test Checklist
 
-1. `godot --path .` starts the game without script errors.
-2. The guard moves and looks around; the building, steps, and sidewalk are visible.
-3. NPCs spawn and approach the entrance during the first minutes.
-4. Looking at an NPC inside the focus cone shows a gold head ring, the person's name, and the HUD target line.
-5. `Space` or left click opens the action wheel; `A`/`D` highlight a slice, `Space` confirms it, `Esc`/right click cancels without a log entry.
-6. `E`/`C` open the inspection/wand panels from the wheel and freeze movement until they close; walking never fires the wand.
-7. Pressing `Q` produces a reaction log entry and reputation feedback.
-8. `E` opens access inspection showing venue-correct artifacts and policy result; `A`/`D` record a decision.
-9. `6` opens the assistance form; submitting shows dispatch feedback.
-10. `R` opens the emergency form; the button must be held ~1.6s or the call cancels.
-11. `G` toggles the flashlight (indicator appears in the HUD); `L` toggles the door lock (indicator turns red when locked).
-12. `F` toggles the debug overlay with NPC states and shift stats.
-13. NPCs route around the building using the navigation mesh (no stuck-at-wall behavior during a smoke run).
-14. When the shift timer reaches 0, the shift review screen shows grade, incident summary, and persisted shift history.
+1. `godot --path .` starts the game on the venue menu without script errors.
+2. Choosing a venue (click or ↑/↓ + Enter) starts that venue's shift and hides the menu.
+3. The guard moves and looks around; the building, steps, and sidewalk are visible.
+4. The guard's camera sits at eye height and the guard stands on the landing, not inside the building.
+5. Walking into the steps carries the guard up onto the landing (steps have colliders).
+6. The skyline backdrop shows silhouettes against the sky, not an opaque black slab.
+7. The `STEP LINE` marquee is readable from the sidewalk.
+8. NPCs spawn and approach the entrance during the first minutes.
+9. Looking at an NPC inside the focus cone shows a gold head ring, the person's name, and the HUD target line.
+10. `Space` or left click opens the action wheel; `A`/`D` highlight a slice, `Space` confirms it, `Esc`/right click cancels without a log entry.
+11. `E`/`C` open the inspection/wand panels from the wheel and freeze movement until they close; walking never fires the wand.
+12. Pressing `Q` produces a reaction log entry and reputation feedback.
+13. `E` opens access inspection showing venue-correct artifacts and policy result; `A`/`D` record a decision.
+14. `6` opens the assistance form; submitting shows dispatch feedback.
+15. `R` opens the emergency form; the button must be held ~1.6s or the call cancels.
+16. `G` toggles the flashlight (indicator appears in the HUD); `L` toggles the door lock (indicator turns red when locked).
+17. `F` toggles the debug overlay with NPC states and shift stats.
+18. `Esc` with nothing open pauses the shift; resume / restart / settings / quit-to-menu all work, and settings changes persist across a restart.
+19. NPCs route around the building using the navigation mesh (no stuck-at-wall behavior during a smoke run).
+20. When the shift timer reaches 0, the shift review screen shows grade, incident summary, and persisted shift history; "Run another shift" returns to the venue menu.
 
 ## Development Workflow