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

src/core/rules.gd

@@ -108,21 +108,6 @@ enum Reaction {
 	CALL_SOMEONE = 8,
 }
 
-## Player dialogue tones.
-enum Tone {
-	PROFESSIONAL = 0,
-	FRIENDLY = 1,
-	FIRM = 2,
-	SUSPICIOUS = 3,
-}
-
-const TONE_NAMES := {
-	Tone.PROFESSIONAL: "Professional",
-	Tone.FRIENDLY: "Friendly",
-	Tone.FIRM: "Firm",
-	Tone.SUSPICIOUS: "Suspicious",
-}
-
 ## Shift phases by time of day.
 enum Phase {
 	EARLY = 0,