chore: PostgreSQL migration compatibility and infrastructure improvements

Database & Migrations:
- Update all Alembic migrations for PostgreSQL compatibility
- Remove SQLite-specific syntax (AUTOINCREMENT, etc.)
- Add database utility helpers for PostgreSQL operations
- Fix services to use PostgreSQL-compatible queries

Documentation:
- Add comprehensive Docker deployment guide
- Add production deployment documentation
- Add infrastructure architecture documentation
- Update database setup guide for PostgreSQL-only
- Expand troubleshooting guide

Architecture & Validation:
- Add migration.yaml rules for SQL compatibility checking
- Enhance validate_architecture.py with migration validation
- Update architecture rules to validate Alembic migrations

Development:
- Fix duplicate install-all target in Makefile
- Add Celery/Redis validation to install.py script
- Add docker-compose.test.yml for CI testing
- Add squash_migrations.py utility script
- Update tests for PostgreSQL compatibility
- Improve test fixtures in conftest.py

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

alembic/versions/2953ed10d22c_add_subscription_billing_tables.py

@@ -10,7 +10,7 @@ from typing import Sequence, Union
 
 from alembic import op
 import sqlalchemy as sa
-from sqlalchemy.dialects import sqlite
+# Removed: from sqlalchemy.dialects import sqlite (using sa.JSON for PostgreSQL)
 
 # revision identifiers, used by Alembic.
 revision: str = '2953ed10d22c'
@@ -36,7 +36,7 @@ def upgrade() -> None:
         sa.Column('products_limit', sa.Integer(), nullable=True),
         sa.Column('team_members', sa.Integer(), nullable=True),
         sa.Column('order_history_months', sa.Integer(), nullable=True),
-        sa.Column('features', sqlite.JSON(), nullable=True),
+        sa.Column('features', sa.JSON(), nullable=True),
         sa.Column('stripe_product_id', sa.String(length=100), nullable=True),
         sa.Column('stripe_price_monthly_id', sa.String(length=100), nullable=True),
         sa.Column('stripe_price_annual_id', sa.String(length=100), nullable=True),
@@ -91,7 +91,7 @@ def upgrade() -> None:
         sa.Column('invoice_pdf_url', sa.String(length=500), nullable=True),
         sa.Column('hosted_invoice_url', sa.String(length=500), nullable=True),
         sa.Column('description', sa.Text(), nullable=True),
-        sa.Column('line_items', sqlite.JSON(), nullable=True),
+        sa.Column('line_items', sa.JSON(), nullable=True),
         sa.Column('created_at', sa.DateTime(), nullable=False),
         sa.Column('updated_at', sa.DateTime(), nullable=False),
         sa.ForeignKeyConstraint(['vendor_id'], ['vendors.id'], ),
@@ -182,7 +182,7 @@ def upgrade() -> None:
         sa.column('products_limit', sa.Integer),
         sa.column('team_members', sa.Integer),
         sa.column('order_history_months', sa.Integer),
-        sa.column('features', sqlite.JSON),
+        sa.column('features', sa.JSON),
         sa.column('display_order', sa.Integer),
         sa.column('is_active', sa.Boolean),
         sa.column('is_public', sa.Boolean),