feat: autocomplete intelligent partage (Forge + CodeMirror)

- autocomplete.js: detection de contexte (mermaid, code, frontmatter, wikilink, markdown)
- Suggestions Mermaid: 15 types + syntaxe par type (flowchart, sequence, class, etc.)
- Suggestions Code: snippets Python/JS/Bash/SQL + 15 langages
- Suggestions Frontmatter: 9 champs YAML
- Suggestions Markdown: titres, formatting, callouts, tableaux
- Wikilinks: [[ cherche dans l'index via API /search/advanced
- Integration Forge: Ctrl+Space, auto-trigger [[ et ```, Tab/Enter pour accepter
- Dropdown flottant positionne au curseur, navigation fleches

frontend/editor-poc.html

@@ -215,10 +215,32 @@ body { font-family: var(--sans); background: var(--bg); color: var(--text); heig
 /* Resize handle between panes */
 .resize-handle { width: 4px; cursor: col-resize; background: var(--border); flex-shrink: 0; transition: background 150ms; }
 .resize-handle:hover { background: var(--accent); }
+
+/* Autocomplete dropdown */
+.ac-dropdown {
+  position: absolute; z-index: 200;
+  background: var(--bg2); border: 1px solid var(--border-md);
+  border-radius: 8px; box-shadow: 0 8px 30px rgba(0,0,0,0.5);
+  min-width: 220px; max-width: 380px; max-height: 260px;
+  overflow-y: auto; display: none; padding: 4px;
+}
+.ac-dropdown.active { display: block; }
+.ac-item {
+  display: flex; align-items: center; gap: 8px;
+  padding: 5px 10px; border-radius: 4px; cursor: pointer;
+  font-size: 12px; color: var(--text);
+}
+.ac-item:hover, .ac-item.active { background: var(--bg-hover); }
+.ac-item-label { font-family: var(--mono); font-weight: 500; white-space: nowrap; }
+.ac-item-detail { font-size: 10.5px; color: var(--text3); margin-left: auto; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 160px; }
+.ac-item-context { font-size: 9px; color: var(--accent); text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 4px; padding: 2px 10px 4px; }
 </style>
 </head>
 <body>
 
+<!-- Autocomplete dropdown -->
+<div class="ac-dropdown" id="ac-dropdown"></div>
+
 <!-- Bar -->
 <div class="bar">
   <div class="bar-left">
@@ -1619,6 +1641,169 @@ body { font-family: var(--sans); background: var(--bg); color: var(--text); heig
     }, 300);
   };
 
+  // ---- Autocomplete (Ctrl+Space or smart trigger) ----
+  var acDropdown = document.getElementById('ac-dropdown');
+  var acItems = [];
+  var acIdx = -1;
+
+  function showAutocomplete(items, context) {
+    acItems = items;
+    acIdx = -1;
+    if (!items.length) { hideAutocomplete(); return; }
+    // Position near cursor
+    var pos = getCaretCoordinates(ta);
+    var rect = ta.getBoundingClientRect();
+    acDropdown.style.left = (rect.left + pos.left - ta.scrollLeft + 20) + 'px';
+    acDropdown.style.top = (rect.top + pos.top - ta.scrollTop + 24) + 'px';
+
+    var html = context ? '<div class="ac-item-context">' + context + '</div>' : '';
+    items.forEach(function(item, i) {
+      html += '<div class="ac-item" data-idx="' + i + '">' +
+        '<span class="ac-item-label">' + escHtml(item.label) + '</span>' +
+        (item.detail ? '<span class="ac-item-detail">' + escHtml(item.detail) + '</span>' : '') +
+        '</div>';
+    });
+    acDropdown.innerHTML = html;
+    acDropdown.classList.add('active');
+    acIdx = 0;
+    highlightAcItem();
+    // Wire clicks
+    acDropdown.querySelectorAll('.ac-item').forEach(function(el) {
+      el.addEventListener('mousedown', function(e) {
+        e.preventDefault();
+        var idx = parseInt(el.dataset.idx);
+        if (!isNaN(idx) && acItems[idx]) applyAutocomplete(acItems[idx]);
+      });
+    });
+  }
+
+  function hideAutocomplete() {
+    acDropdown.classList.remove('active');
+    acItems = [];
+    acIdx = -1;
+  }
+
+  function highlightAcItem() {
+    acDropdown.querySelectorAll('.ac-item').forEach(function(el, i) {
+      el.classList.toggle('active', i === acIdx);
+    });
+    if (acIdx >= 0) {
+      var active = acDropdown.querySelector('.ac-item.active');
+      if (active) active.scrollIntoView({ block: 'nearest' });
+    }
+  }
+
+  function applyAutocomplete(item) {
+    if (!item || !item.insert) return;
+    var start = ta.selectionStart;
+    var end = ta.selectionEnd;
+    var before = ta.value.slice(0, start);
+    var after = ta.value.slice(end);
+
+    // Smart insertion: if we matched a prefix, replace it
+    var lineStart = before.lastIndexOf('\n') + 1;
+    var lineBefore = before.slice(lineStart);
+    var ctx = detectContext(ta.value, start);
+
+    if (ctx.type === 'wikilink') {
+      // Replace [[partial with [[filename]]
+      var bracketPos = before.lastIndexOf('[[');
+      if (bracketPos >= 0) {
+        before = before.slice(0, bracketPos) + '[[' + item.insert;
+        ta.value = before + after;
+        var newPos = before.length;
+        ta.setSelectionRange(newPos, newPos);
+      }
+    } else if (ctx.type === 'frontmatter') {
+      // Replace current line with the field
+      before = before.slice(0, lineStart) + item.insert;
+      ta.value = before + after;
+      ta.setSelectionRange(before.length, before.length);
+    } else {
+      // Standard insert at cursor
+      ta.value = before + item.insert + after;
+      var newPos = start + item.insert.length;
+      ta.setSelectionRange(newPos, newPos);
+    }
+
+    hideAutocomplete();
+    ta.focus();
+    markDirty();
+    autoHeight();
+    updateLineNumbers();
+  }
+
+  function triggerAutocomplete() {
+    var result = suggest(ta.value, ta.selectionStart);
+    if (result.async) {
+      // Wikilink: fetch file list
+      import('/static/js/autocomplete.js').then(function(m) {
+        m.searchWikilinks(result.partial || '', function(items) {
+          showAutocomplete(items, 'Wikilinks');
+        });
+      });
+    } else if (result.items.length > 0) {
+      var ctxLabels = {
+        mermaid: 'Mermaid', code: 'Code', fence_open: 'Langage',
+        frontmatter: 'Frontmatter', markdown: 'Markdown'
+      };
+      showAutocomplete(result.items, ctxLabels[result.context] || result.context);
+    }
+  }
+
+  function getCaretCoordinates(textarea) {
+    var div = document.createElement('div');
+    var style = div.style;
+    var computed = window.getComputedStyle(textarea);
+    for (var key of computed) {
+      try { style[key] = computed[key]; } catch(e) {}
+    }
+    style.position = 'absolute';
+    style.visibility = 'hidden';
+    style.whiteSpace = 'pre-wrap';
+    style.overflow = 'hidden';
+    style.width = textarea.clientWidth + 'px';
+    style.height = 'auto';
+    var pos = textarea.selectionStart;
+    div.textContent = textarea.value.slice(0, pos) + '.';
+    document.body.appendChild(div);
+    var rect = div.getBoundingClientRect();
+    document.body.removeChild(div);
+    return { left: rect.width, top: rect.height };
+  }
+
+  ta.addEventListener('keydown', function(e) {
+    if (acDropdown.classList.contains('active')) {
+      if (e.key === 'ArrowDown') { e.preventDefault(); acIdx = Math.min(acIdx + 1, acItems.length - 1); highlightAcItem(); }
+      else if (e.key === 'ArrowUp') { e.preventDefault(); acIdx = Math.max(acIdx - 1, 0); highlightAcItem(); }
+      else if (e.key === 'Enter' || e.key === 'Tab') {
+        e.preventDefault();
+        if (acIdx >= 0 && acItems[acIdx]) applyAutocomplete(acItems[acIdx]);
+      }
+      else if (e.key === 'Escape') { e.preventDefault(); hideAutocomplete(); }
+      return;
+    }
+    // Ctrl+Space: force autocomplete
+    if ((e.ctrlKey || e.metaKey) && e.key === ' ') {
+      e.preventDefault();
+      triggerAutocomplete();
+    }
+    // Auto-trigger on [[ for wikilinks
+    if (e.key === '[' && ta.selectionStart > 0 && ta.value[ta.selectionStart - 1] === '[') {
+      setTimeout(triggerAutocomplete, 50);
+    }
+  });
+
+  // Trigger on triple backtick
+  ta.addEventListener('input', function() {
+    var before = ta.value.slice(0, ta.selectionStart);
+    if (before.endsWith('``')) {
+      setTimeout(triggerAutocomplete, 50);
+    }
+  });
+
+  function escHtml(s) { return String(s).replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;').replace(/"/g,'&quot;'); }
+
   // ---- Init ----
   updateLineNumbers();