refactor(content): rename mood vocabulary to match voice guide (D-035 Sprint 14 amendment)

Schema and Rust Mood enum renamed for author-friendly vocabulary:
fond→warm, comfortable→content, worried→anxious, concerned→frustrated.
Dropped: analytical (merged into focused), conflicted (modeled as
suspicious+warm collision). Added: hostile. Final 8 moods: anxious,
frustrated, content, suspicious, warm, hostile, relieved, focused.
Neutral = untagged. Resolves Gestalt's blocking issue on #121.

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

server/src/bin/line_preview.rs

@@ -630,13 +630,12 @@ fn topic_str(t: &Topic) -> &'static str {
 
 fn mood_str(m: &Mood) -> &'static str {
     match m {
-        Mood::Fond => "fond",
-        Mood::Comfortable => "comfortable",
-        Mood::Worried => "worried",
+        Mood::Anxious => "anxious",
+        Mood::Frustrated => "frustrated",
+        Mood::Content => "content",
         Mood::Suspicious => "suspicious",
-        Mood::Analytical => "analytical",
-        Mood::Conflicted => "conflicted",
-        Mood::Concerned => "concerned",
+        Mood::Warm => "warm",
+        Mood::Hostile => "hostile",
         Mood::Relieved => "relieved",
         Mood::Focused => "focused",
     }