Amend .claude/rules/multi-tenant-rls.md + prisma-schema.md to name Studio's teamId primitive

feature_id: FEAT-studio-qa

## Context

Amend the Claude Code rulebooks (`.claude/rules/multi-tenant-rls.md` and `.claude/rules/prisma-schema.md`) to name Studio's hybrid `withTeamContext` + Postgres RLS pattern, matching OPER-108. This keeps the two agent-facing rulebooks (Cursor + Claude Code) in sync so autonomous workers write code consistent with the enforcement model.

Ratified by OPER-104 PDT. Docs-only.

## Acceptance Criteria

- `.claude/rules/multi-tenant-rls.md` names both layers: `withTeamContext(teamId)` (app layer) + RLS policies on the sensitive-subset (DB layer).
- `.claude/rules/prisma-schema.md` names the sensitive-subset tables (must match OPER-108).
- `pnpm check:feature-map` passes.
- Zero other rule files modified.