Bump source to 0.9.2 and renumber the 0.x roadmap

- Set project.godot to 0.9.2 and add the matching changelog entry.
- Renumber the postponed work to 0.9.3 UI, 0.9.4 NPC, 0.9.5 textures and 0.9.6 integration, with 0.10.0 as the next minor release candidate.
- Remove the 1.0.0 milestone and post-1.0 planning; plan only 0.x patch/minor increments.
- Synchronize README, PLAN, architecture, status, memory and UI-copy version references.

project.godot

@@ -12,7 +12,7 @@ config_version=5
 
 config/name="Gig Line"
 config/description="Workplace security simulation about observation, access verification, and proportionate escalation."
-config/version="0.9.1"
+config/version="0.9.2"
 run/main_scene="res://scenes/main.tscn"
 config/features=PackedStringArray("4.7", "GL Compatibility")