fix: add unnecessary negative contrast detection to voice linting

- New lint check: 'doesn't just X. They Y' pattern (Claude rhetorical crutch)
- Fixed last instance in judgment essay: 'doesn't just lose income. They lose'
  → 'loses the acknowledgment... The income is secondary.'
- Updated voice-check skill dimension 2 with the pattern description
- Updated AGENTS.md with the new check
- Tightened regex to avoid false positives on legitimate 'isn't only' framing

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Co-Authored-By: Amplifier <240397093+microsoft-amplifier@users.noreply.github.com>

.amplifier/skills/voice-check/SKILL.md

@@ -61,6 +61,12 @@ Does the writing hedge when it should assert? Look for:
   clearly believes
 - Passive constructions that hide the actor ("it was found" vs "I found")
 - False balance ("on the other hand" when there IS no valid other hand)
+- **Unnecessary negative contrast**: the "doesn't just X. They Y" or "isn't
+  only X. It's Y" pattern. This is a Claude rhetorical crutch that creates
+  the *appearance* of depth through contrast without saying anything the
+  second clause didn't already imply. Example: "A doctor doesn't just lose
+  income. They lose the acknowledgment that..." Fix: state Y directly.
+  "A doctor loses the acknowledgment that..."
 
 The voice profile says: "High, earned. States opinions as conclusions from
 experience, not as positions to defend."