feat: add workspace and claude messages support

migrations/20260522000002_workspace_assets.sql

@@ -0,0 +1,34 @@
+-- Workspace assets: local archive for creative outputs from Picture Agent,
+-- ComfyUI Agent, Video Agent and ComfyUI workspaces.
+
+CREATE TABLE IF NOT EXISTS workspace_assets (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    public_id TEXT NOT NULL UNIQUE,
+    user_id INTEGER,
+    source TEXT NOT NULL,
+    kind TEXT NOT NULL,
+    title TEXT,
+    prompt TEXT,
+    model TEXT,
+    status TEXT NOT NULL DEFAULT 'completed',
+    mime_type TEXT,
+    file_name TEXT,
+    file_path TEXT,
+    remote_url TEXT,
+    thumbnail_path TEXT,
+    size_bytes INTEGER NOT NULL DEFAULT 0,
+    metadata TEXT NOT NULL DEFAULT '{}',
+    created_at TEXT NOT NULL DEFAULT (datetime('now')),
+    updated_at TEXT NOT NULL DEFAULT (datetime('now')),
+    deleted_at TEXT,
+    FOREIGN KEY(user_id) REFERENCES users(id) ON DELETE SET NULL
+);
+
+CREATE INDEX IF NOT EXISTS idx_workspace_assets_user_created
+    ON workspace_assets(user_id, created_at DESC);
+CREATE INDEX IF NOT EXISTS idx_workspace_assets_source_created
+    ON workspace_assets(source, created_at DESC);
+CREATE INDEX IF NOT EXISTS idx_workspace_assets_kind_created
+    ON workspace_assets(kind, created_at DESC);
+CREATE INDEX IF NOT EXISTS idx_workspace_assets_deleted
+    ON workspace_assets(deleted_at);