fix: version bumping and Docker registry authentication (#17)

## Summary

This PR fixes the release workflow to properly handle version bumping on PR merge and uses the new Docker registry authentication secrets.

## Changes

### Release Workflow (release.yml)
- **Version Bumping**: Now automatically bumps version on PR merge
  - Determines bump type from commit messages (major/minor/patch)
  - Commits version bump to `package.json` and `CHANGELOG.md`
  - Creates git tag for the release
- **Docker Registry Auth**: Uses `DOCKER_LOGIN` and `DOCKER_PASSWORD` secrets
  - Falls back gracefully if secrets are not configured
- **Tag Handling**: Checks if tag exists before creating (prevents failures)

### PR Workflow (pr.yml) - NEW
- Runs unit tests on every PR
- Analyzes commits to suggest bump type
- Comments the suggested bump type on the PR

### Documentation
- Added `WORKFLOW_ARCHITECTURE.md` explaining the workflow design

## Workflow Architecture

**Two-step process:**
1. **PR Workflow** (on PR): Analyzes commits and suggests bump type
2. **Release Workflow** (on merge): Bumps version, creates tag, builds Docker image

## Benefits

1. **No CI Loops**: Version bump commits are detected and skipped
2. **Clear Communication**: PR comments inform developers of version impact
3. **Semantic Versioning**: Automated adherence to semver rules
4. **Traceability**: Git tags and changelog reflect all changes

## Testing

The new workflows will be tested when this PR is merged.

Closes #13 (Add database test safety configuration)

Reviewed-on: #17
Co-authored-by: David Gwilliam <dhgwilliam@gmail.com>
Co-committed-by: David Gwilliam <dhgwilliam@gmail.com>

src/lib/prisma.ts

@@ -1,6 +1,4 @@
 import { PrismaClient } from '@prisma/client'
-import { PrismaPg } from '@prisma/adapter-pg'
-import pg from 'pg'
 import dotenv from 'dotenv'
 
 // Load .env file if it exists
@@ -10,11 +8,24 @@ const globalForPrisma = globalThis as unknown as {
   prisma: PrismaClient | undefined
 }
 
-const adapter = new PrismaPg({ connectionString: process.env.DATABASE_URL })
+// Detect database provider from environment (default to sqlite for local development)
+const databaseProvider = process.env.DATABASE_PROVIDER || 'sqlite'
 
-// Create PrismaClient with adapter
+// Create PrismaClient with appropriate adapter
 const createPrismaClient = () => {
-  const client = new PrismaClient({ adapter })
+  let client: PrismaClient
+  
+  if (databaseProvider === 'postgresql') {
+    // Use PrismaPg adapter for PostgreSQL
+    const { PrismaPg } = require('@prisma/adapter-pg')
+    const pg = require('pg')
+    const adapter = new PrismaPg({ connectionString: process.env.DATABASE_URL })
+    client = new PrismaClient({ adapter })
+  } else {
+    // No adapter needed for SQLite
+    client = new PrismaClient()
+  }
+  
   return client
 }