feat(v4.0): Settings/Integrations — Gitea + GitHub connect/disconnect matrix

- GitHub integration row ajoutée (🦎 Gitea + 🐙 GitHub)
- Badge 'Primary' sur le provider principal (auth_method)
- Disconnect masqué pour le provider principal
- authMethod, githubLinked, giteaLinked dans Alpine data
- loadGithubStatus() + disconnectGithub() methods
- Matrice respectée: local→déco OK, gitea→déco github OK, github→déco gitea OK

app/db.py

@@ -410,6 +410,58 @@ def init_db():
         """)
         conn.commit()
 
+        # ── v4.0: Account & Integrations ──
+        # 1) auth_method on users
+        try:
+            conn.execute("ALTER TABLE users ADD COLUMN auth_method TEXT DEFAULT 'local'")
+        except sqlite3.OperationalError:
+            pass
+        # Detect existing auth: if user has a gitea_token in user_tokens → 'gitea'
+        conn.execute(
+            "UPDATE users SET auth_method='gitea' WHERE id IN (SELECT gitea_user_id FROM user_tokens)"
+        )
+        conn.execute(
+            "UPDATE users SET auth_method='local' WHERE auth_method IS NULL"
+        )
+        # 2) Publishing & sharing columns on pages
+        try:
+            conn.execute("ALTER TABLE pages ADD COLUMN is_published INTEGER NOT NULL DEFAULT 0")
+        except sqlite3.OperationalError:
+            pass
+        try:
+            conn.execute("ALTER TABLE pages ADD COLUMN publish_slug TEXT DEFAULT ''")
+        except sqlite3.OperationalError:
+            pass
+        try:
+            conn.execute("ALTER TABLE pages ADD COLUMN is_shared INTEGER NOT NULL DEFAULT 0")
+        except sqlite3.OperationalError:
+            pass
+        # 3) page_shares table
+        conn.execute("""
+            CREATE TABLE IF NOT EXISTS page_shares (
+                id INTEGER PRIMARY KEY AUTOINCREMENT,
+                page_id INTEGER NOT NULL REFERENCES pages(id) ON DELETE CASCADE,
+                shared_with_user_id INTEGER REFERENCES users(id),
+                shared_with_email TEXT DEFAULT '',
+                permission TEXT NOT NULL DEFAULT 'view',
+                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+                created_by INTEGER REFERENCES users(id)
+            )
+        """)
+        # 4) recents table
+        conn.execute("""
+            CREATE TABLE IF NOT EXISTS recents (
+                id INTEGER PRIMARY KEY AUTOINCREMENT,
+                user_id INTEGER NOT NULL REFERENCES users(id),
+                page_id INTEGER NOT NULL REFERENCES pages(id),
+                workspace TEXT NOT NULL DEFAULT '',
+                source_type TEXT NOT NULL DEFAULT 'local',
+                accessed_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+                UNIQUE(user_id, page_id)
+            )
+        """)
+        conn.commit()
+
 
 @contextmanager
 def get_conn():