feat(content): v4.6.0 Content Blocks enrichis — Callout, TOC, Math (KaTeX), Toggle, Multi-colonnes

- Ajout blocs enrichis dans l'éditeur: callout (avec sélecteur d'emoji), table of contents (ancres), math (LaTeX/KaTeX), toggle lists (enfants collapsibles), multi-colonnes
- Intégration KaTeX 0.16.11 self-hosté (JS/CSS/fonts) — aucun CDN externe
- Rendu des nouveaux blocs dans les pages publiques (/p/<slug>): TOC, KaTeX, colonnes, toggle <details>
- Persistance 'children' (colonnes/toggle) + export Markdown étendu
- Sidebar customization par utilisateur (config API + colonne sidebar_config)
- Correctif test_views_calendar: parsing des query params year/month (le défaut ouvrait sur le mois courant)
- Tests: 184 passing

static/css/app.css

@@ -380,39 +380,85 @@ input, select, textarea { font-family: inherit; color: inherit; }
   justify-content: space-between;
   padding: 4px 6px;
   border-radius: var(--radius-sm);
+  cursor: pointer;
   transition: background var(--transition);
+  user-select: none;
 }
 
 .sidebar-section-header:hover {
   background: var(--bg-hover);
 }
 
+.sidebar-section-header:active {
+  background: var(--bg-active);
+  transform: scale(0.995);
+}
+
 .sidebar-section-title {
   display: flex;
   align-items: center;
-  gap: var(--space-xs);
+  gap: 3px;
   font-size: 12px;
   font-weight: 600;
   color: var(--text-dim);
   text-transform: none;
   letter-spacing: 0;
+  min-width: 0;
 }
 
 .sidebar-section-title .chevron {
-  font-size: 10px;
-  transition: transform var(--transition);
+  font-size: 8px;
+  width: 14px;
+  height: 14px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  flex-shrink: 0;
+  color: var(--text-muted);
+  transition: transform 180ms ease, color var(--transition);
+  will-change: transform;
 }
 
 .sidebar-section-title .chevron.open {
   transform: rotate(90deg);
+  color: var(--text-secondary);
+}
+
+.sidebar-section-title .section-icon {
+  width: 18px;
+  height: 18px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  flex-shrink: 0;
+  color: var(--text-muted);
+  transition: color var(--transition);
+}
+
+.sidebar-section-header:hover .section-icon {
+  color: var(--text-secondary);
+}
+
+.sidebar-section-title .section-label {
+  flex: 1;
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  color: var(--text-dim);
+  transition: color var(--transition);
+}
+
+.sidebar-section-header:hover .section-label {
+  color: var(--text-secondary);
 }
 
 .sidebar-section-actions {
   display: flex;
   align-items: center;
-  gap: 2px;
+  gap: 1px;
   opacity: 0;
-  transition: opacity var(--transition);
+  transition: opacity 120ms ease;
 }
 
 .sidebar-section-header:hover .sidebar-section-actions {
@@ -426,15 +472,185 @@ input, select, textarea { font-family: inherit; color: inherit; }
   display: flex;
   align-items: center;
   justify-content: center;
-  color: var(--text-secondary);
+  color: var(--text-muted);
   font-size: 14px;
-  transition: background var(--transition);
+  background: none;
+  border: none;
+  cursor: pointer;
+  transition: background var(--transition), color var(--transition);
 }
 
 .section-action-btn:hover {
   background: var(--bg-tertiary);
+  color: var(--text);
 }
 
+/* Section menu (⋮) button */
+.section-menu-btn {
+  font-size: 16px;
+  font-weight: 700;
+  letter-spacing: 1px;
+  opacity: 0.6;
+}
+
+.section-menu-btn:hover {
+  opacity: 1;
+}
+
+/* Section menu dropdown */
+.section-menu-overlay {
+  position: fixed;
+  inset: 0;
+  z-index: 999;
+}
+
+.section-menu {
+  position: fixed;
+  z-index: 1000;
+  min-width: 200px;
+  background: var(--bg-modal);
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  padding: 4px;
+  box-shadow: 0 8px 24px rgba(0,0,0,0.3), 0 2px 6px rgba(0,0,0,0.15);
+}
+
+.section-menu-item {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  padding: 6px 10px;
+  border-radius: 5px;
+  cursor: pointer;
+  font-size: 13px;
+  color: var(--text);
+  transition: background 120ms;
+}
+
+.section-menu-item:hover {
+  background: var(--bg-hover);
+}
+
+.section-menu-item .smi-icon {
+  width: 18px;
+  text-align: center;
+  font-size: 14px;
+  flex-shrink: 0;
+}
+
+.section-menu-item .smi-label {
+  flex: 1;
+}
+
+.section-menu-item .smi-check {
+  color: var(--accent);
+  font-size: 14px;
+}
+
+.section-menu-sep {
+  height: 1px;
+  background: var(--border);
+  margin: 4px 8px;
+}
+
+.section-menu-customize {
+  border-top: 1px solid var(--border);
+  margin-top: 2px;
+  padding-top: 8px;
+}
+
+/* Customize Sidebar Panel */
+.sidebar-customize-panel {
+  padding: 8px 12px;
+}
+
+.scp-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  margin-bottom: 8px;
+  padding: 4px 0;
+}
+
+.scp-title {
+  font-size: 14px;
+  font-weight: 600;
+  color: var(--text);
+}
+
+.scp-done {
+  font-size: 13px;
+  color: var(--accent);
+  background: none;
+  border: none;
+  cursor: pointer;
+  padding: 4px 12px;
+  border-radius: 6px;
+  transition: background 120ms;
+  font-weight: 500;
+}
+
+.scp-done:hover {
+  background: var(--bg-hover);
+}
+
+.scp-list {
+  display: flex;
+  flex-direction: column;
+  gap: 1px;
+}
+
+.scp-item {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 6px 8px;
+  border-radius: 6px;
+  cursor: pointer;
+  transition: background 120ms;
+}
+
+.scp-item:hover {
+  background: var(--bg-hover);
+}
+
+.scp-item-left {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.scp-item-icon {
+  font-size: 16px;
+  width: 22px;
+  text-align: center;
+  flex-shrink: 0;
+}
+
+.scp-item-name {
+  font-size: 13px;
+  color: var(--text);
+}
+
+.scp-item-eye {
+  font-size: 16px;
+  opacity: 0.7;
+}
+
+.scp-item-eye-off {
+  opacity: 0.3;
+}
+
+.customize-overlay {
+  position: fixed;
+  inset: 0;
+  background: rgba(0,0,0,0.3);
+  z-index: 998;
+}
+
+/* x-cloak for Alpine.js */
+[x-cloak] { display: none !important; }
+
 /* Sidebar items (pages) */
 .sidebar-items {
   list-style: none;
@@ -2197,6 +2413,12 @@ button.breadcrumb-current { max-width: 260px; }
 
 /* Toggle */
 .block-toggle {
+  display: flex;
+  flex-direction: column;
+  align-items: stretch;
+  gap: 2px;
+}
+.toggle-title-row {
   display: flex;
   align-items: flex-start;
   gap: 4px;
@@ -2221,7 +2443,7 @@ button.breadcrumb-current { max-width: 260px; }
 .toggle-chevron:hover {
   background: var(--bg-hover);
 }
-.block-toggle div {
+.block-toggle .toggle-title {
   flex: 1;
   outline: none;
   font-size: 16px;
@@ -2289,18 +2511,216 @@ button.breadcrumb-current { max-width: 260px; }
   padding: 14px 16px;
   border-radius: 4px;
   margin: 4px 0;
+  position: relative;
 }
 .block-callout .callout-icon {
   font-size: 20px;
   flex-shrink: 0;
+  cursor: pointer;
+  transition: transform .1s ease;
 }
-.block-callout div {
+.block-callout .callout-icon:hover {
+  transform: scale(1.1);
+}
+.block-callout > div[data-bid] {
   flex: 1;
   outline: none;
   font-size: 16px;
   line-height: 1.6;
   min-height: 24px;
 }
+.callout-icon-picker {
+  position: absolute;
+  top: calc(100% + 4px);
+  left: 12px;
+  z-index: 50;
+  display: flex;
+  flex-wrap: wrap;
+  gap: 2px;
+  width: 236px;
+  max-width: 90%;
+  padding: 8px;
+  background: var(--bg-modal);
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  box-shadow: var(--shadow-modal);
+}
+.callout-icon-opt {
+  background: transparent;
+  border: none;
+  font-size: 18px;
+  width: 34px;
+  height: 34px;
+  border-radius: 5px;
+  cursor: pointer;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+}
+.callout-icon-opt:hover {
+  background: var(--bg-hover);
+}
+
+/* Toggle children */
+.toggle-children {
+  margin-left: 22px;
+  padding-left: 12px;
+  border-left: 1px solid var(--border);
+  margin-top: 2px;
+}
+
+/* Table of Contents */
+.block-toc {
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  padding: 16px 20px;
+  margin: 4px 0;
+}
+.block-toc-title {
+  font-size: 13px;
+  font-weight: 600;
+  text-transform: uppercase;
+  letter-spacing: .5px;
+  color: var(--text-dim);
+  margin-bottom: 10px;
+}
+.block-toc-item {
+  font-size: 14px;
+  color: var(--text-primary);
+  padding: 5px 8px;
+  border-radius: 4px;
+  cursor: pointer;
+  line-height: 1.4;
+}
+.block-toc-item:hover {
+  background: var(--bg-hover);
+  color: var(--accent);
+}
+.block-toc-empty {
+  color: var(--text-dim);
+  font-size: 14px;
+  font-style: italic;
+  padding: 12px 16px;
+}
+
+/* Math block */
+.block-math {
+  margin: 8px 0;
+}
+.math-display {
+  min-height: 40px;
+  padding: 10px 14px;
+  background: var(--bg-secondary);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  overflow-x: auto;
+  font-size: 15px;
+}
+.math-editor {
+  width: 100%;
+  margin-top: 6px;
+  padding: 8px 10px;
+  background: var(--bg-tertiary);
+  border: 1px dashed var(--border);
+  border-radius: 6px;
+  color: var(--text-primary);
+  font-family: 'SF Mono', 'Fira Code', monospace;
+  font-size: 13px;
+  outline: none;
+  resize: vertical;
+  min-height: 40px;
+  box-sizing: border-box;
+}
+.math-editor:focus {
+  border-color: var(--accent);
+}
+
+/* Column list */
+.block-columns {
+  margin: 8px 0 16px;
+}
+.columns-add-bar {
+  margin-bottom: 4px;
+}
+.columns-add-btn {
+  background: transparent;
+  border: 1px dashed var(--border);
+  color: var(--text-dim);
+  padding: 6px 14px;
+  border-radius: 6px;
+  font-size: 13px;
+  cursor: pointer;
+  transition: border-color .15s, color .15s;
+}
+.columns-add-btn:hover {
+  border-color: var(--accent);
+  color: var(--accent);
+}
+.columns-row {
+  display: flex;
+  gap: 12px;
+  align-items: stretch;
+}
+.column-cell {
+  flex: 1;
+  min-width: 0;
+}
+.block-column-wrapper {
+  position: relative;
+  padding: 10px 12px;
+  background: var(--bg-secondary);
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  height: 100%;
+  box-sizing: border-box;
+}
+.block-column-wrapper:hover .block-handle {
+  opacity: 1;
+}
+.block-column-wrapper .block-actions {
+  right: -8px;
+  top: -8px;
+}
+.block-column-wrapper .block-add-btn {
+  background: var(--bg-modal);
+  border: 1px solid var(--border);
+  width: 20px;
+  height: 20px;
+  font-size: 13px;
+  border-radius: 50%;
+  line-height: 1;
+}
+.block-column {
+  outline: none;
+  min-height: 24px;
+  font-size: 15px;
+  line-height: 1.6;
+  color: var(--text-primary);
+  word-break: break-word;
+}
+.block-columns .block-wrapper {
+  margin: 0;
+  background: transparent;
+}
+.block-columns .block-handle {
+  opacity: 0;
+}
+.block-nested {
+  outline: none;
+  min-height: 24px;
+  font-size: 15px;
+  line-height: 1.6;
+  color: var(--text-primary);
+  word-break: break-word;
+}
+.nested-block {
+  margin: 2px 0;
+}
+.nested-block .block-handle {
+  display: none;
+}
+
+
 
 /* Image block */
 .block-image-wrapper {