Add Ogg Vorbis decoding support via microVorbis

[kahrendt]

Decode Ogg Vorbis alongside the existing FLAC/MP3/Opus/WAV codecs, following the same patterns.

• Add AudioFileType::VORBIS, AudioDecoder::decode_vorbis(), and build wiring (CMake option, FetchContent of micro-vorbis v0.1.0, Kconfig, idf_component.yml dependency).
• Detect plain Ogg (audio/ogg, application/ogg, .ogg) as Vorbis; Opus needs an explicit signal (audio/opus, codecs=opus, .opus). The classification is the same in every build: a type whose codec is compiled out yields NONE rather than the other Ogg codec.
• Extend the decode_benchmark example with a Vorbis clip.
• Update README, INTEGRATION, and CLAUDE docs.

[Copilot]

Pull request overview

Adds Ogg Vorbis decoding to micro-decoder (alongside the existing FLAC/MP3/Opus/WAV support) using the micro-vorbis library, and updates build/config wiring plus documentation/examples to match the new codec matrix and Ogg detection rules.

Changes:

• Introduces AudioFileType::VORBIS and a Vorbis decode path in AudioDecoder backed by micro_vorbis::OggVorbisDecoder.
• Updates format detection logic so “plain Ogg” resolves to Vorbis and Opus requires an explicit signal (content-type or .opus extension), with “compiled-out codec => NONE” behavior.
• Adds build system toggles/dependencies (CMake, Kconfig, ESP-IDF component manifest) and extends the decode benchmark + docs/README accordingly.

Reviewed changes

Copilot reviewed 15 out of 16 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/types.cpp	Updates Content-Type / extension detection to distinguish Opus vs Vorbis within Ogg.
src/audio_decoder.h	Adds micro-vorbis include, decoder method declaration, and Vorbis decoder member.
src/audio_decoder.cpp	Wires Vorbis into start()/decode switch and implements decode_vorbis().
include/micro_decoder/types.h	Adds AudioFileType::VORBIS and adjusts enum numeric assignments.
cmake/host.cmake	Adds host CMake option + FetchContent wiring for micro-vorbis.
cmake/esp-idf.cmake	Maps CONFIG_MICRO_DECODER_CODEC_VORBIS to MICRO_DECODER_CODEC_VORBIS.
Kconfig	Adds MICRO_DECODER_CODEC_VORBIS toggle.
idf_component.yml	Adds micro-vorbis managed dependency and updates description.
examples/decode_benchmark/src/main.cpp	Adds a Vorbis clip to the benchmark run list.
examples/decode_benchmark/sdkconfig.defaults	Enables Vorbis in the benchmark default config.
examples/decode_benchmark/README.md	Updates benchmark docs/results to include Vorbis.
examples/decode_benchmark/convert_audio.py	Adds Vorbis encode step when generating embedded test audio.
README.md	Updates top-level feature/docs text to include Vorbis.
docs/INTEGRATION.md	Documents Ogg ambiguity rules and adds a recognized types table including Vorbis.
CLAUDE.md	Updates internal “codec listing order” convention to include Vorbis.

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