GitHub App integration and LLM-powered changelog pipeline

Automated LLM changelog generation — Commits are now analyzed by an LLM (OpenAI or Anthropic) and turned into publishable changelog entries. Entries are validated, stored as rendered Markdown and JSON, and can be auto-published or held for approval per project settings.

You can install the GitHub App and connect repositories from the UI; the app records installation details and provides a repo picker.integrations
When you create a project the system performs a full historical commit sync and queues per-commit changelog generation.backend

Added versioned endpoints under /v1 — GitHub callback, repo listing for an installation, and project creation (POST /v1/projects).backend

Diffs are filtered to remove noisy files (lockfiles, build output, vendored deps, generated code, large binaries) before analysis so changelogs focus on meaningful changes.backend
LLM calls use structured output and Zod validation so generated entries are consistent and safe to publish.backend
Processing priority can be elevated via entitlement so important accounts get faster syncs and LLM analysis.devops
User BYOK (Vault) support added for LLM API keys; Vault RPC helpers and a Vault client are included.devops

Updated README and product docs with GitHub App setup, required env vars, API versioning, diff-filter behaviour, and test commands.