Sync opam package metadata including x-maintenance-intent
and external dependency specifications.

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

- Rename Peertube module references to Peer_tube in client library
- Refactor bushel_peertube to use generated Peer_tube types
- Remove hand-coded JSON codecs in favor of generated ones
- Add helper functions to extract values from Jsont.json for untyped fields

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

- Add default value support: extract JSON defaults and generate OCaml literals
for bools, ints, floats, strings, enums, null, and empty arrays
- Generate constructors with optional params using ?(name=default) syntax
- Generate jsont codecs with ~dec_absent:default for absent field handling
- Add runtime validation for strings (minLength, maxLength, pattern),
numbers (minimum, maximum, exclusiveMinimum, exclusiveMaximum),
and lists (minItems, maxItems, uniqueItems)
- Add field-level union types for primitive oneOf/anyOf schemas
- Handle forward references in circular dependencies with Jsont.json fallback
- Improve topological sort to handle cycles gracefully
- Regenerate immich and peertube clients with new features

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

- Add YAML support to openapi-gen CLI using yamlt library
- Fix recursive schema handling (self-referential types use Jsont.json)
- Fix topological sort to ignore self-dependencies
- Fix newline before @param in generated doc comments
- Generate PeerTube library from official OpenAPI spec (v8.0.0)
- Add peertube_auth library with OAuth2 session management
- Add peertube CLI with auth commands (login, logout, status, profiles)
- Remove old hand-written PeerTube library modules

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