feat: implement nib design system — warm amber palette, dual themes, new typography

Replace Tokyonight/Catppuccin blue palette with warm amber/ink identity.
Dual theme support (noir + paper) via data-theme attribute with
localStorage persistence. Space Grotesk for chrome, Monaspace Neon for
content. Updated glyph set (Strokes: — ○ ◇) across web and CLI.

internal/display/glyph.go

@@ -3,8 +3,8 @@ package display
 import "github.com/lerko/nib/internal/db"
 
 var glyphMap = map[db.Glyph]string{
-	db.GlyphNote:  "◦",
-	db.GlyphTodo:  "▸",
+	db.GlyphNote:  "—",
+	db.GlyphTodo:  "○",
 	db.GlyphEvent: "◇",
 }
 
@@ -25,7 +25,7 @@ func DisplayGlyph(glyph db.Glyph, cardType *db.CardType) string {
 	if g, ok := glyphMap[glyph]; ok {
 		return g
 	}
-	return "◦"
+	return "—"
 }
 
 func FormatID(id string) string {