Rename Assistants to Teammates

[mistercrunch]

Summary

Big-bang rename of Agor's product entity from Assistant/Assistants to Teammate / AI teammate across product surfaces.

This PR intentionally treats the rename as a pre-1.0 breaking change where useful, while preserving cheap compatibility for legacy serialized state, routes, docs redirects, and framework detection.

Highlights

• Renames user-facing UI copy, routes, settings sections, onboarding/create flows, branch modal labels, global search/home surfaces, and teammate creation metadata.
• Adds canonical teammate core types/helpers (TeammateConfig, isTeammate, getTeammateConfig) while keeping deprecated assistant aliases for cheap compatibility.
• Renames board primary pointer to primary_teammate_id in schema/repository/API surfaces.
• Adds teammate-named daemon custom methods, welcome-note helpers, knowledge namespace helpers, and MCP tools.
• Updates docs and marketing copy to make /guide/teammates canonical; /guide/assistants remains a legacy redirect-style page.
• Preserves protocol/model-role assistant terminology for chat message roles, provider events, SDK event parsing, and other true LLM protocol contexts.

Compatibility / migrations

• New writes use custom_context.teammate.kind = 'teammate'.
• Legacy readers continue to accept custom_context.assistant and custom_context.agent where cheap.
• Postgres migration physically renames boards.primary_assistant_id to primary_teammate_id.
• SQLite migration adds primary_teammate_id and keeps the legacy primary_assistant_id column as compatibility to avoid a destructive local table rebuild; repository reads fall back to the legacy value.
• Legacy docs route /guide/assistants points users to /guide/teammates.
• Legacy framework repo detection for preset-io/agor-assistant remains while canonical copy points at preset-io/agor-teammate.

Validation

• pnpm i
• pnpm check
• pnpm --filter @agor/core test -- src/templates/assistant-welcome-note.test.ts src/db/repositories/boards.test.ts
• pnpm --filter agor-ui test -- src/utils/assistantWelcomeNote.test.ts src/components/BranchModal/BranchModal.test.tsx
• pnpm --filter @agor/daemon test -- src/mcp/tools/knowledge.test.ts src/services/branches.test.ts src/services/boards.test.ts src/services/assistant-knowledge.test.ts

Notes

• pnpm i completed successfully; node-pty logged a native build fallback because make is unavailable in this environment.
• Remaining assistant hits should primarily be intentional protocol/model-role references, deprecated compatibility aliases, or historical redirect artifacts.