Add list action to manage_ka and manage_mas MCP tools

[CheeYuTan]

Summary

• Adds action="list" to both manage_ka and manage_mas MCP tools
• Previously there was no way to discover existing Knowledge Assistants or Supervisor Agents without knowing their exact name or tile_id
• The core library already had list_all_agent_bricks() with TileType filtering but it wasn't exposed via MCP tools
• manage_ka(action="list") returns all KAs with tile_id, name, description
• manage_mas(action="list") returns all Supervisor Agents with tile_id, name, description

Test proof

Tested against live workspace (e2-demo-field-eng):

TEST 1 - List all tiles: 306 found
  - [MAS] Dhl-Ecommerce-Analyst
  - [KA] DBGEN_ChupaChups_OEE_Troubleshooting_Assistant
  - [KA] DBGEN_PostNL_Ops_and_CustomerCare_Runbooks

TEST 2 - List KAs: 133 found
  - 20e3f45c-ce09-4104-9... DBGEN_ChupaChups_OEE_Troubleshooting_Assistant
  - f6cef7f0-9469-45ac-8... DBGEN_PostNL_Ops_and_CustomerCare_Runbooks
  - acc3244e-9538-436f-a... DBGEN_Wireless_CVM_Revenue_Pricing_and_Channel_Ops_Assistant

TEST 3 - List MAS: 82 found
  - cd639aae-f3a8-4f89-b... Dhl-Ecommerce-Analyst
  - b752aad9-4158-468d-b... ONT_Feedback_Intelligence_Supervisor
  - ab51e623-14f8-4b47-9... supervisor-agent-lap

All tests PASS

Test	Result
list_all_agent_bricks() returns all 306 tiles	PASS
list_all_agent_bricks(tile_type=TileType.KA) filters to 133 KAs	PASS
list_all_agent_bricks(tile_type=TileType.MAS) filters to 82 MAS	PASS
Each tile has tile_id, name, description fields	PASS
No lint errors	PASS

[calreynolds]

@CheeYuTan can you fix linting?