brand identity overhaul: match BRAND-IDENTITY.md across all pages

Design system changes (per brand guide):
- ZERO rounded-2xl/3xl remaining (was 131 instances)
- ZERO bg-gradient remaining (was 25) — all solid colors
- ZERO colored shadows (shadow-trust-blue, etc) — flat, no glow
- ZERO backdrop-blur/glass effects — solid backgrounds
- ZERO emoji in logo marks — square P logomark everywhere
- ZERO decorative scale animations (group-hover:scale-105, etc)

Tailwind config:
- Added brand color names: midnight, promise-blue, generosity-gold, fulfilled-green, alert-red, paper
- Kept legacy aliases (trust-blue, etc) for backwards compat
- --radius: 0.75rem → 0.5rem (tighter corners)

CSS:
- Removed glass, glass-dark, card-hover, pulse-ring, bounce-gentle, confetti-fall, scale-in animations
- Kept only purposeful animations: fadeUp, fadeIn, slideDown, shimmer, counter-roll
- --primary tuned to match Promise Blue exactly

Components:
- Button: removed all colored shadows, added 'blue' variant, removed rounded from sizes
- All UI components: rounded-xl/2xl → rounded-lg

Pages updated (41 files):
- Dashboard layout: solid header (no blur), border-l-2 active indicator, midnight logo mark
- Login/Signup: paper bg (no gradient), midnight logo mark, no emoji
- Pledge flow: solid color icons, no gradient progress bars
- All dashboard pages: flat, sharp, editorial

pledge-now-pay-later/tailwind.config.ts

@@ -42,6 +42,14 @@ const config: Config = {
         border: "hsl(var(--border))",
         input: "hsl(var(--input))",
         ring: "hsl(var(--ring))",
+        // Brand colors — named by psychology, not appearance
+        midnight: "#111827",
+        "promise-blue": "#1e40af",
+        "generosity-gold": "#f59e0b",
+        "fulfilled-green": "#16a34a",
+        "alert-red": "#dc2626",
+        paper: "#f9fafb",
+        // Legacy aliases (used across codebase)
         "trust-blue": "#1e40af",
         "warm-amber": "#f59e0b",
         "success-green": "#16a34a",