feat(library): tags + tag filtering, monochrome icons; fix live tag updates

- library: expose page tags (batch), render tag chips per row and add a tag
  filter bar; register tag create/associate/remove in the shared context menu
  exactly like local-workspace
- library: restore monochrome SVG icons (folder/edit/image/file) matching
  local-workspace, with optional custom page_icon
- workspace: refresh tag chips/filter live on tag add/remove (reassign arrays
  + tagsVersion) instead of requiring a page reload
- ctxmenu: measure the rendered menu and clamp it to the viewport on open

app/routers/library.py

@@ -69,6 +69,7 @@ def _build_item(db_row: dict, uid: int = 1) -> dict:
         "id": page_id,
         "title": title,
         "icon": icon,
+        "page_icon": db_row.get("page_icon") or "",
         "is_folder": bool(db_row.get("is_folder", 0)),
         "source_type": source_type,
         "source_label": _source_label(source_type, workspace),
@@ -84,6 +85,7 @@ def _build_item(db_row: dict, uid: int = 1) -> dict:
         "content_format": content_format,
         "favorited": bool(db_row.get("favorited", 0)),
         "share_mode": db_row.get("share_mode", "private"),
+        "tags": [],
     }
 
 
@@ -98,7 +100,30 @@ def _apply_source_filter(query: str, params: list, source_type: str) -> tuple[st
 
 
 def _rows_to_items(rows, uid: int = 1) -> list:
-    return [_build_item(dict(r), uid) for r in rows]
+    items = [_build_item(dict(r), uid) for r in rows]
+    return _attach_tags(items)
+
+
+def _attach_tags(items: list) -> list:
+    """Batch-load page tags for library items."""
+    if not items:
+        return items
+    ids = [it["id"] for it in items]
+    placeholders = ",".join("?" for _ in ids)
+    with get_conn() as conn:
+        rows = conn.execute(
+            f"SELECT pt.page_id, t.id, t.name, t.color FROM page_tags pt "
+            f"JOIN tags t ON t.id = pt.tag_id WHERE pt.page_id IN ({placeholders})",
+            ids,
+        ).fetchall()
+    tag_map: dict = {}
+    for r in rows:
+        tag_map.setdefault(r["page_id"], []).append({
+            "id": r["id"], "name": r["name"], "color": r["color"],
+        })
+    for it in items:
+        it["tags"] = tag_map.get(it["id"], [])
+    return items
 
 
 def _enrich_children(items: list) -> list:
@@ -124,7 +149,7 @@ def _enrich_children(items: list) -> list:
 
 BASE_SELECT = (
     "SELECT p.id, p.title, p.workspace, p.updated_at, p.content_format, "
-    "p.parent_id, p.share_mode, p.parent_section"
+    "p.parent_id, p.share_mode, p.parent_section, p.page_icon"
 )
 
 
@@ -361,6 +386,8 @@ async def library_local_workspace_children(item_id: int, request: Request):
             "url": f"/local-workspace?folder={r['id']}" if is_folder else f"/pages/{r['id']}",
             "content_format": r["content_format"] or "file",
             "favorited": False,
+            "page_icon": "",
+            "tags": [],
             "size_display": _format_size(r["size"]) if r["size"] else "",
         })
 
@@ -469,6 +496,8 @@ async def library_local_workspace(
             "url": f"/local-workspace?folder={r['id']}" if is_folder else f"/pages/{r['id']}",
             "content_format": r["content_format"] or "file",
             "favorited": False,
+            "page_icon": "",
+            "tags": [],
             "size_display": _format_size(r["size"]) if r["size"] else "",
         })