Add two usage patterns and three future-enhancement proposals

[Copilot]

Summary

Extends the usage patterns catalogue with two patterns covering currently-supported but undocumented features, and proposes three future patterns as GitHub issues.

New pattern files

• Automated Integration Tests (docs/patterns/automated-integration-tests.md) — embeds Counterfact in a Jest/Vitest suite via beforeAll/afterAll using the programmatic API; shows contextRegistry for per-test flag toggling
• Custom Middleware (docs/patterns/custom-middleware.md) — covers _.middleware.ts for auth gates, response headers (with randomUUID import), request logging, and scoped admin-only middleware

Index updates (docs/usage-patterns.md)

• Two new rows in the pattern table
• Updated intro paragraph to reference the new patterns

Issue proposals (.github/issue-proposals/) — all parented to #1805

• docs-pattern-record-and-replay.md — --record flag to capture proxy traffic into handler files
• docs-pattern-webhook-simulation.md — $.webhook() helper for outbound push events
• docs-pattern-persistent-state.md — --persist-state to serialize/restore context across restarts

Original Prompt

Issue: More usage patterns

Review the usage patterns and suggest candidates that haven't been documented yet. Include patterns that Counterfact doesn't support but should be considered for future enhancements.

Manual acceptance tests

• docs/usage-patterns.md table contains rows for Automated Integration Tests and Custom Middleware; intro paragraph references both
• docs/patterns/automated-integration-tests.md renders with a complete beforeAll/afterAll example using a shared config object (no duplicate config literal)
• docs/patterns/custom-middleware.md renders with import { randomUUID } from "node:crypto" in the response-headers example
• Three new files exist under .github/issue-proposals/ with valid YAML front matter (parentIssue: 1805) and non-empty bodies
• All existing pattern files and cross-links are unchanged

Tasks

• Added docs/patterns/automated-integration-tests.md documenting programmatic API usage in test suites
• Added docs/patterns/custom-middleware.md documenting _.middleware.ts for cross-cutting concerns
• Updated docs/usage-patterns.md table and intro paragraph
• Created issue proposals for Record and Replay, Webhook Simulation, and Persistent State
• Added .changeset/more-usage-patterns.md