# Task ID: 120

**Title:** Add AgentProject junction model

**Status:** pending

**Dependencies:** None

**Priority:** high

**Description:** Add AgentProject many-to-many junction table linking Agents to Projects with role and optional LLM override

**Details:**

In src/db/prisma/schema.prisma add:
1. model AgentProject with: id, agentId, projectId, role (@default("developer")), llmId?, createdAt
2. Relations: agent (Agent), project (Project), llm (Llm?)
3. @@unique([agentId, projectId]), @@index([agentId]), @@index([projectId])
4. Add projectMemberships AgentProject[] to Agent model
5. Add agentMemberships AgentProject[] to Project model
6. Add agentProjects AgentProject[] to Llm model
7. Keep Agent.projectId for backward compatibility (one release)

**Test Strategy:**

Schema tests: create AgentProject junction, verify unique constraint prevents duplicate membership, test cascade on both Agent and Project delete, test SetNull on Llm delete.