Run 1 Changelog: API Proxy Publish

Summary of changes made in Run 1 of the Frontend Implementation project.

Repository: `api-proxy`

Published version: @arda-cards/api-proxy@1.0.0 (GitHub Packages)

RequestContext type (src/shared/types.ts) — per-request user identity carrying author, tenantId, userId for BFF header forwarding.
RequestOptions type (src/shared/http-client.ts) — optional per-request options: context?: RequestContext, contentType?: string.
generateRequestId option on ProxyConfig — pluggable request ID generator with crypto.randomUUID() default.
processUploadJob() on ItemProxy — POST /upload-job/{jobId} trigger.
Preparation-phase methods (committed as prerequisite): createImageUploadUrl(), deleteDraft(), 8 lookup methods (lookupDepartments through lookupUsecases), bulkCreate(), bulkUpdate(), getQueryPage(), getHistoryPage().
Types: ImageUploadRequest, ImageUploadResponse, BulkUpdateEntry, BulkUpdateRequest.

HttpClient.request() sends Authorization: Bearer header on every request (previously sent API key only as X-Author).
All proxy methods across all 8 proxy classes accept optional RequestOptions as last parameter.
X-Request-ID header sent on every request (UUID v4 default, configurable).
Minimum Node version raised to >=20.0.0 (from >=18.18.0) for crypto.randomUUID() support.
Coverage thresholds raised from 80% to 90% (lines and branches).