feat: sous-pages — parent_id, sidebar hiérarchique, bouton +New sub-page

- DB: parent_id dans table pages (ALTER TABLE migration auto)
- Sidebar: pages parent_id IS NULL affichées, sous-pages indentées en dessous
- API: create_page accepte parent_id (0 = racine)
- JS: newSubPage extrait page ID et passe parent_id
- page_editor: liste les sous-pages + bouton '+ New sub-page'

app/db.py

@@ -137,10 +137,16 @@ def init_db():
                 title TEXT NOT NULL DEFAULT 'New page',
                 content TEXT NOT NULL DEFAULT '',
                 parent_section TEXT DEFAULT 'Private',
+                parent_id INTEGER REFERENCES pages(id),
                 created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                 updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
             );
         """)
+        # Migration: add parent_id if missing (v1.0.0+)
+        try:
+            conn.execute("ALTER TABLE pages ADD COLUMN parent_id INTEGER REFERENCES pages(id)")
+        except sqlite3.OperationalError:
+            pass
         conn.commit()
 
 

app/routers/board.py

@@ -139,7 +139,7 @@ def _sidebar_data(request: Request, owner: str = "", repo: str = "") -> dict:
     # Load pages for this project workspace
     with get_conn() as conn:
         pages = conn.execute(
-            "SELECT id, title, updated_at FROM pages WHERE workspace=? ORDER BY updated_at DESC LIMIT 10",
+            "SELECT id, title, parent_id, updated_at FROM pages WHERE workspace=? AND parent_id IS NULL ORDER BY updated_at DESC LIMIT 10",
             (ws_key,),
         ).fetchall()
         for p in pages:
@@ -147,6 +147,16 @@ def _sidebar_data(request: Request, owner: str = "", repo: str = "") -> dict:
                 "id": f"page/{p['id']}", "name": p["title"], "icon": "📄",
                 "url": f"/pages/{p['id']}", "active": False, "indent": 0,
             })
+            # Load sub-pages
+            subs = conn.execute(
+                "SELECT id, title FROM pages WHERE parent_id=? ORDER BY updated_at DESC",
+                (p["id"],),
+            ).fetchall()
+            for sp in subs:
+                recent.append({
+                    "id": f"page/{sp['id']}", "name": sp["title"], "icon": "·",
+                    "url": f"/pages/{sp['id']}", "active": False, "indent": 1,
+                })
     return {"workspace_name": ws_name, "workspace_initial": ws_name[0].upper() if ws_name else "B",
             "current_page": repo or "Dashboard", "last_edited": "now",
             "recent_pages": recent, "private_pages": [r for r in recent if r.get("active") or r["id"].startswith("page/")],
@@ -439,18 +449,19 @@ async def extract_ai_keywords(owner: str, repo: str):
 @router.post("/api/pages")
 async def create_page(request: Request, title: str = Query(default="New page"),
                        section: str = Query(default="Private"),
-                       project: str = Query(default="")):
-    """Create a new Markdown page in the given project workspace."""
+                       project: str = Query(default=""),
+                       parent_id: int = Query(default=0)):
+    """Create a new Markdown page, optionally as a sub-page."""
     user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
     ws_key = project if project else (user.get("login", "Bruno") if user else "Bruno")
     with get_conn() as conn:
         cur = conn.execute(
-            "INSERT INTO pages (workspace, title, parent_section) VALUES (?,?,?)",
-            (ws_key, title, section),
+            "INSERT INTO pages (workspace, title, parent_section, parent_id) VALUES (?,?,?,?)",
+            (ws_key, title, section, parent_id if parent_id > 0 else None),
         )
         conn.commit()
         page_id = cur.lastrowid
-    return {"status": "ok", "id": page_id, "title": title, "workspace": ws_key}
+    return {"status": "ok", "id": page_id, "title": title, "workspace": ws_key, "parent_id": parent_id}
 
 
 @router.get("/api/pages/{page_id}")

app/routers/dashboard.py

@@ -71,7 +71,13 @@ async def view_page_root(request: Request, page_id: int):
     parts = ws.split("/") if "/" in ws else ["", ""]
     owner, repo = parts[0], parts[1] if len(parts) > 1 else ""
     sidebar = board_sidebar(request, owner, repo)
-    ctx = {**sidebar, "page": page}
+    # Load sub-pages
+    with get_conn() as conn:
+        subs = conn.execute(
+            "SELECT id, title FROM pages WHERE parent_id=? ORDER BY updated_at DESC",
+            (page_id,),
+        ).fetchall()
+    ctx = {**sidebar, "page": page, "sub_pages": [dict(s) for s in subs]}
     template = env.get_template("page_editor.html")
     return template.render(**ctx)
 

app/templates/base.html

@@ -436,7 +436,8 @@
       },
       newSubPage(parentId) {
         const project = this.workspaceKey || '';
-        fetch(`/board/api/pages?title=New%20page&section=Private&project=${encodeURIComponent(project)}`, {
+        const pid = parentId.replace('page/', '');
+        fetch(`/board/api/pages?title=New%20sub-page&section=Private&project=${encodeURIComponent(project)}&parent_id=${pid}`, {
           method: 'POST',
           headers: { 'X-CSRF-Token': this.getCsrfToken() }
         })

app/templates/page_editor.html

@@ -69,11 +69,36 @@
       <button class="sidebar-new-chat" style="width:auto; padding:8px 16px;" @click="insertMd('# Meeting Notes\n\n**Date:** \n**Attendees:** \n\n## Agenda\n\n- \n\n## Notes\n\n- \n\n## Action Items\n\n- [ ] \n', '')">🎤 Meeting Notes</button>
     </div>
   </div>
+
+  <!-- Sub-pages -->
+  <div style="margin-top:32px; border-top:1px solid var(--border); padding-top:16px;">
+    <h3 style="font-size:14px; font-weight:600; margin-bottom:12px;">Sub-pages</h3>
+    {% for sub in sub_pages %}
+    <a href="/pages/{{ sub.id }}" style="display:flex; align-items:center; gap:8px; padding:6px 8px; border-radius:6px; text-decoration:none; color:var(--text-primary); font-size:13px;"
+       onmouseover="this.style.background='var(--bg-hover)'" onmouseout="this.style.background='transparent'">
+      <span>📄</span> {{ sub.title }}
+    </a>
+    {% endfor %}
+    <button class="kanban-new-card" style="margin-top:8px;"
+            @click="createSubPage()">+ New sub-page</button>
+  </div>
 </div>
 {% endblock %}
 
 {% block scripts %}
 <script>
+  function createSubPage() {
+    const csrf = document.cookie.match(/csrf_token=([^;]+)/);
+    const token = csrf ? csrf[1] : '';
+    const project = document.querySelector('[x-data]')?.__x?.$data?.workspaceKey || '';
+    fetch(`/board/api/pages?title=New%20sub-page&section=Private&project=${encodeURIComponent(project)}&parent_id={{ page.id }}`, {
+      method: 'POST',
+      headers: { 'X-CSRF-Token': token }
+    })
+      .then(r => r.json())
+      .then(data => { window.location.href = `/pages/${data.id}`; })
+      .catch(err => { alert('Failed: ' + err.message); });
+  }
   // Simple Markdown-to-HTML renderer
   function renderMarkdown(md) {
     let html = md