feat(server): adapt Hubble 2.0 frontend APIs and implement default graph/role management

[Yeaury]

Purpose of the PR

Adapt API endpoints required by the Hubble 2.0 frontend to achieve feature parity with the internal version. The community edition of HugeGraph Server currently lacks several critical APIs that the Hubble frontend depends on (graph profile listing, default graph management, default role management, schema templates, etc.), preventing the Hubble frontend from properly using core graph and role management features. This PR adds the missing APIs to enable full integration between the Hubble 2.0 frontend and the community edition Server.

Main Changes

1. GraphsAPI — Graph Management Endpoint Enhancements (GraphsAPI.java)

• GET /graphspaces/{graphspace}/graphs/profile — New graph profile listing endpoint with prefix filtering, default-graph-first sorting, and full config info (nickname, create_time, default status, etc.)
• GET /graphspaces/{graphspace}/graphs/{name}/default — Set a graph as default
• GET /graphspaces/{graphspace}/graphs/{name}/undefault — Unset a graph as default
• GET /graphspaces/{graphspace}/graphs/default — Get current user's default graph list
• PUT /graphspaces/{graphspace}/graphs/{name} — Graph management operations (currently supports update action for nickname updates)
• POST /graphspaces/{graphspace}/graphs (form-urlencoded) — Hubble frontend form-based graph creation compatibility
• Auto-fill HStore/PD mode defaults (backend=hstore, serializer=binary, store={name}) during graph creation, and map frontend schema field to schema.init_template

2. GraphSpaceAPI — Default Role Management (GraphSpaceAPI.java)

• POST /graphspaces/{graphspace}/role — Create default role (supports SPACE/ANALYST/OBSERVER)
• GET /graphspaces/{graphspace}/role — Check if a user/group has a specified default role
• DELETE /graphspaces/{graphspace}/role — Delete default role
• Remove unnecessary PD mode restriction from listProfile endpoint
• Add @JsonIgnoreProperties(ignoreUnknown = true) to tolerate unknown fields from the frontend

3. ManagerAPI — Role Query (ManagerAPI.java)

• GET /auth/manager/default — New endpoint for Hubble frontend to query if the current user has a specified default role

4. SchemaTemplateAPI — Schema Template CRUD (New File)

• GET /graphspaces/{graphspace}/schematemplates — List all schema templates
• GET /graphspaces/{graphspace}/schematemplates/{name} — Get a specific template
• POST /graphspaces/{graphspace}/schematemplates — Create template
• PUT /graphspaces/{graphspace}/schematemplates/{name} — Update template
• DELETE /graphspaces/{graphspace}/schematemplates/{name} — Delete template

5. Authentication & Authorization Layer (AuthManager.java, StandardAuthManager.java, StandardAuthManagerV2.java, HugeGraphAuthProxy.java)

• Added 10 new methods to AuthManager interface: setDefaultGraph/unsetDefaultGraph/getDefaultGraph and createDefaultRole/createSpaceDefaultRole/isDefaultRole/deleteDefaultRole, etc.
• StandardAuthManager and StandardAuthManagerV2 implement the above interfaces using existing HugeGroup/HugeBelong/HugeRole metadata mechanisms
• HugeGraphAuthProxy.AuthManagerProxy adds corresponding delegate methods to properly forward calls to the underlying authManager

6. Utilities (ConfigUtil.java, GraphManager.java)

• ConfigUtil.writeConfigToString() — New utility method to serialize graph configuration to string (used by the listProfile endpoint)
• GraphManager — Added graph management helper methods

Verifying these changes

• Need tests and can be verified as follows:
  • Verify the full graph management flow via Hubble frontend (create graph, list, profile query)
  • Verify default graph set/unset/query via Hubble frontend
  • Verify Schema template CRUD operations
  • Verify default role (SPACE/ANALYST/OBSERVER) creation, query, and deletion
  • Directly test all new endpoints via REST API

Does this PR potentially affect the following parts?

• Dependencies (add/update license info & regenerate_known_dependencies.sh)
• Modify configurations
• The public API
• Other affects (typed here)
• Nope

Documentation Status

• Doc - TODO
• Doc - Done
• Doc - No Need