fix: Scaffolding improvements and Redis multi-tenancy support

[jdutton]

Summary

This PR addresses scaffolding issues discovered during canary project testing and adds Redis key prefix support for multi-tenant deployments.

Part 1: Scaffolding Fixes

Issue #1: Workspace path aliases breaking module resolution (CRITICAL)

• Problem: Scaffolded vitest.config.ts included workspace aliases (@mcp-typescript-simple/tools: '../tools/src') that only work in monorepo environments
• Solution: Removed resolve.alias configuration - packages now resolve from node_modules
• Impact: Tests and builds now work correctly in standalone scaffolded projects

Issue #2: Cannot scaffold into existing directory

• Problem: Common workflow blocked: clone GitHub repo → scaffold into it
• Solution: Accept "." as special case to scaffold into current directory, using directory name as project name
• Impact: npx create-mcp-typescript-simple@next . --yes now works

Issue #3: Port configuration documentation

• Problem: Port conflicts can cause test failures, but users don't know how to change ports
• Solution: Added helpful comments in vitest.system.config.ts explaining port configuration
• Impact: Users understand how to resolve port conflicts

Issue #4: System tests failing out-of-the-box

• Problem: Scaffolded projects had system tests failing with CORS errors (14 failed | 2 passed)
• Root Cause: ALLOWED_ORIGINS set in test environment + NODE_ENV=development instead of 'test'
• Solution: Removed ALLOWED_ORIGINS from test environment, changed NODE_ENV to 'test'
• Impact: System tests now pass (16/16) in fresh scaffolds

Code Quality

• Refactored index.ts to reduce cognitive complexity (extracted helper functions for validation and config)

Part 2: Redis Multi-Tenancy Support

Problem

Multiple MCP apps sharing the same Redis instance had key conflicts:

• Both mcp-typescript-simple and mcp-typescript-simple-canary write to oauth:client:abc123
• Required separate Redis instances or databases

Solution

Added REDIS_KEY_PREFIX environment variable with automatic normalization:

• Implementation: DRY helper functions, updated all 6 Redis stores and factories
• Backward compatible: Empty prefix by default (existing deployments unaffected)
• Auto-normalization: mcp-main → mcp-main: (colon separator added automatically)
• Documentation: Added to all .env templates with default value mcp-persistence

Impact

Can now run multiple MCP apps on same Redis instance:

# Main app
REDIS_KEY_PREFIX=mcp-main
# Keys: mcp-main:oauth:client:, mcp-main:mcp:session:, etc.

# Canary app  
REDIS_KEY_PREFIX=mcp-canary
# Keys: mcp-canary:oauth:client:, mcp-canary:mcp:session:, etc.

Testing

• ✅ All validation passed (typecheck, lint, build, tests)
• ✅ Tested scaffolding into new directory
• ✅ Tested scaffolding into current directory with "."
• ✅ System tests pass (16/16) in fresh scaffolds
• ✅ Backward compatible: empty REDIS_KEY_PREFIX works as before

Files Changed: 26

Config & Core:

• packages/config/src/storage-config.ts - Added REDIS_KEY_PREFIX schema
• packages/persistence/src/stores/redis/redis-utils.ts - Added DRY helpers

Redis Stores (6 files):

• Updated all Redis stores to accept keyPrefix parameter

Factories (6 files):

• Updated all factories to pass keyPrefix from environment

Scaffolding Templates (8 files):

• Fixed vitest.config.ts, vitest.system.config.ts, vitest-global-setup.ts
• Added REDIS_KEY_PREFIX to all .env templates

Other:

• packages/create-mcp-typescript-simple/src/index.ts - Current directory support + refactoring
• packages/create-mcp-typescript-simple/src/generator.ts - Allow current directory scaffolding
• CHANGELOG.md - Added v0.9.1-rc.2 release notes

Release Plan

After merge, release as v0.9.1-rc.2 for canary project testing.

🤖 Generated with Claude Code

[sonarqubecloud]

Quality Gate failed

Failed conditions
3.9% Duplication on New Code (required ≤ 3%)

See analysis details on SonarQube Cloud