[verified] Security hardening + UX/UI polish

Security (requesting-code-review pipeline + independent reviewer):
- Fix path traversal on file upload (basename sanitize + resolve-containment)
- Fix IDOR: org + owner scoping on all group/chat routes (_authorize_group/_get_owned_group),
  hide other users' personal groups in listings
- Remove XSS via v-html in Chat task (text interpolation)
- Add test_security.py (traversal + cross-user denial) — all pass

UX/UI (ui-ux-pro-max + frontend-dev-verification):
- Global: focus rings, 44px touch targets, hover/press transitions, input focus glow,
  prefers-reduced-motion, skeleton loaders, empty states, back links, spinner
- Login: password toggle, autocomplete, spinner, disabled-when-empty
- Cards lift on hover; dashboard skeleton + empty state; analyze button spinner

All backend tests pass (m0/m1/routes/security/e2e); frontend builds; served SPA verified via curl.

backend/app/api/group_routes.py

@@ -29,6 +29,30 @@ def _stores():
     }
 
 
+def _authorize_group(group: dict) -> None:
+    """Enforce org-scoped access (IDOR defense). super_admin may access any org.
+
+    Private/personal groups (owner_user_id set) are only accessible by their owner
+    (or super_admin), even within the same org.
+    """
+    actor = current_user()
+    if actor.get("role") == "super_admin":
+        return
+    owner = group.get("owner_user_id")
+    if owner and owner != actor["id"]:
+        raise ApiError("permission denied", 403)
+    if group.get("org_id") != actor.get("org_id"):
+        raise ApiError("permission denied", 403)
+
+
+def _get_owned_group(s, gid: str) -> dict:
+    group = s["groups"].get_or_none(gid)
+    if not group:
+        raise ApiError("group not found", 404)
+    _authorize_group(group)
+    return group
+
+
 def _upload_dir():
     d = Config.DATA_DIR / "uploads"
     d.mkdir(parents=True, exist_ok=True)
@@ -46,10 +70,21 @@ def create_group():
 
     if request.files:
         for file in request.files.getlist("files"):
-            ext = (file.filename or "").rsplit(".", 1)[-1].lower()
+            raw_name = file.filename or ""
+            # Path traversal defense: take only the basename, drop any directory
+            # segments and reject empty/unsafe names. Never trust client filename as a path.
+            safe_name = Path(raw_name).name
+            if not safe_name or safe_name in (".", "..", "/", "\\") or "/" in raw_name or "\\" in raw_name:
+                raise ApiError("invalid file name")
+            ext = safe_name.rsplit(".", 1)[-1].lower()
             if ext not in Config.ALLOWED_UPLOAD_EXTS:
                 raise ApiError(f"unsupported file type: {ext}")
-            dest = _upload_dir() / f"{current_user()['id'].replace('@','_')}__{file.filename}"
+            dest = _upload_dir() / f"{current_user()['id'].replace('@','_')}__{safe_name}"
+            # Ensure resolved path stays inside the upload dir (defense in depth).
+            try:
+                dest.resolve(strict=False).relative_to(_upload_dir().resolve(strict=True))
+            except ValueError:
+                raise ApiError("invalid file path")
             file.save(dest)
             saved_files.append(dest.name)
 
@@ -95,6 +130,13 @@ def list_groups():
     visible = s["groups"].list_visible_to(
         role=actor.get("role"), org_id=actor.get("org_id")
     )
+    # Expose personal/private groups only to their owner (IDOR defense in listing).
+    if actor.get("role") != "super_admin":
+        visible = [
+            g
+            for g in visible
+            if not g.get("owner_user_id") or g.get("owner_user_id") == actor["id"]
+        ]
     return jsonify({"groups": visible})
 
 
@@ -104,11 +146,7 @@ def list_groups():
 def analyze_group(gid: str):
     """Run analysis: sales kit + 15 personas. Synchronous for v1 (replaces gen)."""
     s = _stores()
-    group = s["groups"].get_or_none(gid)
-    if not group:
-        raise ApiError("group not found", 404)
-    if group.get("org_id") != (current_user().get("org_id") or "org-default"):
-        raise ApiError("permission denied", 403)
+    group = _get_owned_group(s, gid)
 
     inp = group.get("input", {})
     if not s["llm"]:
@@ -152,12 +190,8 @@ def analyze_group(gid: str):
 @require_auth
 def get_group(gid: str):
     s = _stores()
-    group = s["groups"].get_or_none(gid)
-    if not group:
-        raise ApiError("group not found", 404)
+    group = _get_owned_group(s, gid)
     actor = current_user()
-    if actor.get("role") != "super_admin" and group.get("org_id") != actor.get("org_id"):
-        raise ApiError("permission denied", 403)
 
     view = dict(group)
     if actor.get("role") == "user":
@@ -172,9 +206,7 @@ def get_group(gid: str):
 @require_auth
 def list_personas(gid: str):
     s = _stores()
-    group = s["groups"].get_or_none(gid)
-    if not group:
-        raise ApiError("group not found", 404)
+    group = _get_owned_group(s, gid)
     actor = current_user()
     if actor.get("role") == "user":
         if group.get("status") != "ready":
@@ -197,9 +229,7 @@ def list_personas(gid: str):
 @require_auth
 def get_persona(gid: str, pid: str):
     s = _stores()
-    group = s["groups"].get_or_none(gid)
-    if not group:
-        raise ApiError("group not found", 404)
+    group = _get_owned_group(s, gid)
     p = s["groups"].get_persona(gid, pid)
     if not p:
         raise ApiError("persona not found", 404)
@@ -215,9 +245,7 @@ def get_persona(gid: str, pid: str):
 @require_roles("admin")
 def update_persona(gid: str, pid: str):
     s = _stores()
-    group = s["groups"].get_or_none(gid)
-    if not group:
-        raise ApiError("group not found", 404)
+    _get_owned_group(s, gid)
     data = request.get_json(silent=True) or {}
     try:
         updated = s["groups"].update_persona(gid, pid, data)