feat: sweep complet — tous les émojis → outline SVG icons

Templates modifiés (22 fichiers):
- _icons.html: +14 new icons (paperclip, external-link, sparkles, lightbulb, tag,
  file-text, save, upload, trending-up, zap, alert-triangle, user, eye-off)
- base.html: +8 JS icons, 🦎🐙🔑🔗👁📋🔲📑❓⚠️→SVG
- page_editor.html: 43→0 émojis (📎📄🔒🔗⭐📋📁✨📝🗄📑📊📅🗓🖼📥🌐✏💬💡 etc)
- settings.html: 30→0 (⚙️📋🏷🧩👥💾🙈👁🔒🌙☀️🌳📊📝⚠🦎✅🐙🔗✏🗑)
- local_workspace.html: 25→0 (📄📁✏🗑⚠📋➕)
- gitea_workspace.html: 25→0 (🔗📄📤🔄⚙📁📄🔒✏🗑💾)
- board.html: 13→0 (📁📊📋☰📈👥✕✓🗑⚡🔍)
- workspace.html: 11→0 (🏠🔑⚙📁🔗📂🐙)
- landing.html: 8→0 (📚🚀📝📊🦎🌐🔒⚡)
- trash.html, table_view, dashboard, accounts, card_detail, public_page,
  workspaces, team_load, notes, _header, detailed_board, card, board_fragment
- Ajouté import _icons.html aux fragments standalone
- 143 tests passent

app/templates/accounts.html

@@ -1,12 +1,12 @@
 {% extends "base.html" %}
-{% block page_icon %}👤{% endblock %}
+{% block page_icon %}{{ fd_icon("user",18) }}{% endblock %}
 {% block page_title %}Accounts{% endblock %}
 {% block title_prefix %}Accounts{% endblock %}
 
 {% block content %}
 <div class="page-title-area">
   <div class="page-title">
-    <span class="page-icon-lg">👤</span>
+    <span class="page-icon-lg">{{ fd_icon("user",24) }}</span>
     <h1>Account Management</h1>
   </div>
 </div>
@@ -50,7 +50,7 @@
   <div style="background:var(--bg-secondary); border-radius:8px; padding:20px; margin-bottom:24px;">
     <h3 style="margin-bottom:12px;">Connected Accounts</h3>
     <div style="display:flex; align-items:center; gap:12px; padding:12px; border:1px solid var(--border); border-radius:6px;">
-      <span style="font-size:20px;">🔗</span>
+      <span style="font-size:20px;">{{ fd_icon("link",20) }}</span>
       <div style="flex:1;">
         <div style="font-weight:600;">Gitea</div>
         <div style="font-size:12px; color:var(--text-dim);">