docs(docs): replace Commonwealth with Settled Reach across docs

Updated in-universe "Commonwealth" references to "the Settled Reach"
in decisions, architecture docs, design docs, workshop outputs,
README, and wiki. Kept all references to Hamilton's books as
inspiration/comparison in historical discussions and wiki-review
workshop rounds.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/workshops/content-gap-analysis_v0_1/round1-araminta.md

@@ -42,7 +42,7 @@ That's it. No style guide for art we haven't made. No font selection for UI that
 
 ### Proposed v0.1 Color Palette
 
-The Commonwealth is sleek, advanced, subtle. Even at boxes-with-labels fidelity, we can communicate mood.
+The Settled Reach is sleek, advanced, subtle. Even at boxes-with-labels fidelity, we can communicate mood.
 
 **Background/Environment:**
 - `#1a1a2e` - Deep navy. Base floor/ground. The station is dimly lit by default.
@@ -330,7 +330,7 @@ Even if we have zero audio files in v0.1, the sound model works through these vi
 
 **Audio direction for later:**
 I'd defer actual audio content entirely from v0.1. The visual indicator system proves the sound model mechanically. Adding audio is additive polish, not structural. When we do add audio:
-- Ambient: low drone, station hum, ventilation. The Commonwealth is a machine. It breathes.
+- Ambient: low drone, station hum, ventilation. The Settled Reach is a machine. It breathes.
 - Close range: footsteps on metal, door mechanisms, muffled conversation bleed.
 - No music in gameplay. Music in menus/loading only. The station's ambient sound IS the soundtrack.