Palettes variees, logo stamp croque, search/date modernises

- Palettes : Chagrine bleu lavande + ambre + rose ancien (moins aquatique),
  Grave ocre rouge + ardoise (plus lumineux), Zen vert franc + sienne + canard
  (pas de pastels glauques), Peps secondary indigo
- Logo : icone dans stamp carre rotate(-10deg), separe du texte, hover -16deg
- Login : logo stamp rotate -10deg, subtitle epure
- Search : UInput/USelect remplaces par champs custom accent-soft + icone
- Dates : icone clock + opacity 0.7
- Badges : UBadge remplace par pills custom uppercase accent

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

frontend/app/pages/decisions/index.vue

@@ -105,27 +105,28 @@ function formatDate(dateStr: string): string {
   >
     <!-- Search / sort bar -->
     <template #search>
-      <UInput
-        v-model="searchQuery"
-        placeholder="Rechercher une decision..."
-        icon="i-lucide-search"
-        size="sm"
-        class="w-full sm:w-64"
-      />
-      <USelect
-        v-model="sortBy"
-        :items="sortOptions"
-        size="sm"
-        class="w-36"
-      />
-      <UButton
+      <div class="search-field">
+        <UIcon name="i-lucide-search" class="search-field__icon" />
+        <input
+          v-model="searchQuery"
+          type="text"
+          class="search-field__input"
+          placeholder="Rechercher une decision..."
+        />
+      </div>
+      <select v-model="sortBy" class="sort-select">
+        <option v-for="opt in sortOptions" :key="opt.value" :value="opt.value">
+          {{ opt.label }}
+        </option>
+      </select>
+      <NuxtLink
         v-if="auth.isAuthenticated"
         to="/decisions/new"
-        label="Nouvelle"
-        icon="i-lucide-plus"
-        color="primary"
-        size="sm"
-      />
+        class="action-btn"
+      >
+        <UIcon name="i-lucide-plus" class="text-xs" />
+        <span>Nouvelle</span>
+      </NuxtLink>
     </template>
 
     <!-- Main content: decision list -->
@@ -175,14 +176,15 @@ function formatDate(dateStr: string): string {
           </div>
 
           <div class="decision-card__meta">
-            <UBadge variant="subtle" color="primary" size="xs">
+            <span class="decision-card__type-badge">
               {{ typeLabel(decision.decision_type) }}
-            </UBadge>
+            </span>
             <span class="decision-card__steps">
               <UIcon name="i-lucide-layers" class="text-xs" />
               {{ decision.steps.length }} etape{{ decision.steps.length !== 1 ? 's' : '' }}
             </span>
             <span class="decision-card__date">
+              <UIcon name="i-lucide-clock" class="text-xs" />
               {{ formatDate(decision.created_at) }}
             </span>
           </div>
@@ -305,9 +307,13 @@ function formatDate(dateStr: string): string {
 }
 
 .decision-card__date {
+  display: inline-flex;
+  align-items: center;
+  gap: 0.25rem;
   font-size: 0.75rem;
   color: var(--mood-text-muted);
   margin-left: auto;
+  opacity: 0.7;
 }
 
 @media (min-width: 640px) {
@@ -316,6 +322,86 @@ function formatDate(dateStr: string): string {
   }
 }
 
+.decision-card__type-badge {
+  font-size: 0.6875rem;
+  font-weight: 700;
+  text-transform: uppercase;
+  letter-spacing: 0.04em;
+  padding: 3px 10px;
+  border-radius: 20px;
+  background: var(--mood-accent-soft);
+  color: var(--mood-accent);
+}
+
+/* --- Modern search / sort / action --- */
+.search-field {
+  flex: 1;
+  min-width: 10rem;
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  padding: 0.625rem 1rem;
+  background: var(--mood-accent-soft);
+  border-radius: 12px;
+  transition: box-shadow 0.15s ease;
+}
+.search-field:focus-within {
+  box-shadow: 0 0 0 2.5px var(--mood-accent-soft);
+}
+.search-field__icon {
+  color: var(--mood-text-muted);
+  opacity: 0.5;
+  font-size: 0.875rem;
+  flex-shrink: 0;
+}
+.search-field__input {
+  flex: 1;
+  background: none;
+  font-size: 0.9375rem;
+  color: var(--mood-text);
+  min-width: 0;
+}
+.search-field__input::placeholder {
+  color: var(--mood-text-muted);
+  opacity: 0.4;
+}
+
+.sort-select {
+  padding: 0.625rem 1rem;
+  font-size: 0.875rem;
+  font-weight: 600;
+  color: var(--mood-text);
+  background: var(--mood-accent-soft);
+  border-radius: 12px;
+  cursor: pointer;
+  appearance: none;
+  -webkit-appearance: none;
+  min-width: 5.5rem;
+}
+
+.action-btn {
+  display: inline-flex;
+  align-items: center;
+  gap: 0.375rem;
+  padding: 0.625rem 1.25rem;
+  font-size: 0.875rem;
+  font-weight: 700;
+  color: var(--mood-accent-text);
+  background: var(--mood-accent);
+  border-radius: 20px;
+  cursor: pointer;
+  text-decoration: none;
+  transition: transform 0.12s ease, box-shadow 0.12s ease;
+  white-space: nowrap;
+}
+.action-btn:hover {
+  transform: translateY(-1px);
+  box-shadow: 0 4px 12px var(--mood-shadow);
+}
+.action-btn:active {
+  transform: translateY(0);
+}
+
 .toolbox-section-title {
   font-size: 0.8125rem;
   font-weight: 700;