Remove dialogue tone-of-voice system, add Gitea Actions full build, add venue cycling

- Delete Rules.Tone/TONE_NAMES, NpcProfile.tone_modifiers, tone params on
  NPCController.roll_reaction/apply_player_action; dialogue_lines flattened
  to Array[String]; HUD tone label, T binding, and hud.tone_prefix removed
- Docs updated everywhere (PLAN, README, DONE, MEMORY); PLAN section heading
  'Tone and Design Direction' -> 'Design Direction'
- Add .gitea/workflows/build.yml: checks job (import+tests) on push/PR; full
  build job (export templates, Linux/Windows/macOS exports, artifact upload,
  and tag-based Gitea release publish via GITEA_TOKEN) on tags/dispatch
- Remove old .github/workflows/ci.yml to avoid double runs
- Add venue cycling (V) across all three scenarios with hud.venue_switched
- Refresh README screenshots to match the new HUD
- 53/53 tests pass, boot smoke clean

content/strings.en.json

@@ -1,6 +1,5 @@
 {
-  "hud.controls": "Q polite direction · 1-3 simple gestures · 4 warning · 5 block · 6 assist · R emergency · E inspect / close · W wand · A allow · D deny · T tone · G flashlight · L lock door · F debug",
-  "hud.tone_prefix": "Tone: %s",
+  "hud.controls": "Q polite direction · 1-3 simple gestures · 4 warning · 5 block · 6 assist · R emergency · E inspect / close · W wand · A allow · D deny · V venue · G flashlight · L lock door · F debug",
   "hud.escalation_prefix": "Escalation: %s",
   "hud.cooldown": "EMERGENCY RADIO COOLDOWN: %.0fs",
   "hud.aim_first": "Aim at someone first.",
@@ -39,5 +38,6 @@
   "door.unlocked": "The door is now unlocked.",
   "door.thwarted": "%s tries the locked door and fails.",
   "flashlight.on": "Flashlight on.",
-  "flashlight.off": "Flashlight off."
+  "flashlight.off": "Flashlight off.",
+  "hud.venue_switched": "Venue: %s"
 }