style(visual-fidelity): components — batches B,E,G,H

- B: token-equivalent rgba → color-mix in SignupFlowOverlay, OnboardingWidget
- E: drop text-white Tailwind utility from ImageUpload remove-button (now color: var(--parch-text) inline)
- G: typography off-scale snaps (9→10, 14→13, 15→16, 19→18 px)
- H: padding off-scale snaps in BoardPostCard/Form, CirclePicker, FilterBar, LoginModal

app/components/LoginModal.vue

@@ -40,7 +40,7 @@
                 type="email"
                 placeholder="your.email@example.com"
                 required
-              />
+              >
             </div>
 
             <div class="info-box">
@@ -182,7 +182,7 @@ onUnmounted(() => document.removeEventListener('keydown', handleKeydown))
 
 .modal-overline {
   font-family: 'Brygada 1918', serif;
-  font-size: 14px;
+  font-size: 13px;
   font-weight: 600;
   color: var(--candle);
   margin-bottom: 12px;
@@ -218,7 +218,7 @@ onUnmounted(() => document.removeEventListener('keydown', handleKeydown))
 .info-box {
   font-size: 11px;
   color: var(--text-faint);
-  padding: 10px 14px;
+  padding: 12px 16px;
   border: 1px dashed var(--border);
   margin-bottom: 16px;
   line-height: 1.6;