docs: Add Javadoc documentation to all public symbols (#25)

* docs: Add Javadoc documentation to all public symbols

Added comprehensive Boost-style Javadoc documentation comments to all
public symbols in the include/boost/capy directory, including:

- datastore.hpp: class and member documentation
- polystore_fwd.hpp: forward declaration comment
- brotli.hpp: file-level documentation
- brotli/encode.hpp: enums, constants, service interface, and functions
- brotli/decode.hpp: enums, result codes, service interface, and functions
- brotli/shared_dictionary.hpp: enum and service documentation
- zlib.hpp: file-level documentation
- zlib/stream.hpp: structure and member documentation
- zlib/deflate.hpp: service interface and all member functions
- zlib/inflate.hpp: service interface and all member functions
- zlib/flush.hpp: enum values with descriptions
- zlib/compression_level.hpp: compression level constants
- zlib/compression_method.hpp: compression method constants
- zlib/compression_strategy.hpp: strategy constants with explanations
- zlib/data_type.hpp: data type constants

All documentation follows Boost C++ Libraries Javadoc conventions with:
- Brief descriptions starting with appropriate verb forms
- @param tags for function parameters
- @return tags for return values
- Proper formatting and structure

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Vinnie Falco <vinniefalco@users.noreply.github.com>

* docs: Enhance documentation with detailed descriptions and examples

Added comprehensive descriptions explaining what each component does
and how to use it. Included practical code examples demonstrating:
- Brotli compression/decompression (one-shot and streaming)
- ZLib deflate/inflate operations with different formats
- Compression levels, strategies, and flush modes
- Stream state management and datastore usage

All examples follow Boost-style Javadoc conventions with @code blocks.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Vinnie Falco <vinniefalco@users.noreply.github.com>

---------

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>
Co-authored-by: Vinnie Falco <vinniefalco@users.noreply.github.com>

Author: vinniefalco

include/boost/capy/brotli.hpp

@@ -7,6 +7,30 @@
 // Official repository: https://github.com/cppalliance/capy
 //
 
+/** @file
+    Brotli compression and decompression library.
+
+    This header includes all Brotli-related functionality including
+    encoding, decoding, error handling, and shared dictionary support.
+
+    Brotli is a generic-purpose lossless compression algorithm that compresses
+    data using a combination of a modern variant of the LZ77 algorithm, Huffman
+    coding and 2nd order context modeling, with a compression ratio comparable
+    to the best currently available general-purpose compression methods.
+
+    @code
+    #include <boost/capy/brotli.hpp>
+    #include <boost/capy/datastore.hpp>
+
+    // Create a datastore for services
+    boost::capy::datastore ctx;
+
+    // Install compression and decompression services
+    auto& encoder = boost::capy::brotli::install_encode_service(ctx);
+    auto& decoder = boost::capy::brotli::install_decode_service(ctx);
+    @endcode
+*/
+
 #ifndef BOOST_CAPY_BROTLI_HPP
 #define BOOST_CAPY_BROTLI_HPP
 

include/boost/capy/brotli/decode.hpp

@@ -22,19 +22,36 @@ namespace brotli {
 /** Opaque structure that holds decoder state. */
 struct decoder_state;
 
-/** Result type for decompress and decompress_stream functions. */
+/** Decoder result codes.
+
+    These values indicate the result of decompression operations.
+*/
 enum class decoder_result
 {
+    /** Decompression error occurred. */
     error = 0,
+
+    /** Decompression completed successfully. */
     success = 1,
+
+    /** More input data is needed. */
     needs_more_input = 2,
+
+    /** More output space is needed. */
     needs_more_output = 3
 };
 
-/** Options to be used with set_parameter. */
+/** Decoder parameter identifiers.
+
+    These values identify parameters that can be set
+    on a decoder instance.
+*/
 enum class decoder_param
 {
+    /** Disable automatic ring buffer reallocation. */
     disable_ring_buffer_reallocation = 0,
+
+    /** Enable large window mode. */
     large_window = 1
 };
 
@@ -44,32 +61,112 @@ using metadata_start_func = void (*)(void* opaque, std::size_t size);
 /** Callback to fire on metadata block chunk becomes available. */
 using metadata_chunk_func = void (*)(void* opaque, const std::uint8_t* data, std::size_t size);
 
-/** Provides the Brotli decompression API */
+/** Provides the Brotli decompression API.
+
+    This service interface exposes Brotli decoder functionality
+    through a set of virtual functions. The decoder can operate
+    in one-shot mode for simple decompression or streaming mode
+    for processing data in chunks.
+
+    @code
+    // Example: Simple one-shot decompression
+    boost::capy::datastore ctx;
+    auto& decoder = boost::capy::brotli::install_decode_service(ctx);
+
+    std::vector<std::uint8_t> compressed_data = get_compressed_data();
+    std::vector<std::uint8_t> output(1024 * 1024); // 1MB buffer
+    std::size_t decoded_size = output.size();
+
+    auto result = decoder.decompress(
+        compressed_data.size(),
+        compressed_data.data(),
+        &decoded_size,
+        output.data());
+
+    if (result == boost::capy::brotli::decoder_result::success)
+    {
+        output.resize(decoded_size);
+        // Use decompressed data
+    }
+    @endcode
+
+    @code
+    // Example: Streaming decompression
+    auto* state = decoder.create_instance(nullptr, nullptr, nullptr);
+
+    std::size_t available_in = compressed_data.size();
+    const std::uint8_t* next_in = compressed_data.data();
+    std::size_t available_out = output.size();
+    std::uint8_t* next_out = output.data();
+    std::size_t total_out = 0;
+
+    auto result = decoder.decompress_stream(
+        state,
+        &available_in,
+        &next_in,
+        &available_out,
+        &next_out,
+        &total_out);
+
+    decoder.destroy_instance(state);
+    @endcode
+*/
 struct BOOST_SYMBOL_VISIBLE
     decode_service
 {
+    /** Set a decoder parameter.
+        @param state The decoder state.
+        @param param The parameter identifier.
+        @param value The parameter value.
+        @return True on success, false on error.
+    */
     virtual bool
     set_parameter(
         decoder_state* state,
         decoder_param param,
         std::uint32_t value) const noexcept = 0;
 
+    /** Create a new decoder instance.
+        @param alloc_func Allocation function.
+        @param free_func Deallocation function.
+        @param opaque Opaque pointer passed to allocation functions.
+        @return Pointer to decoder state, or nullptr on error.
+    */
     virtual decoder_state*
     create_instance(
         alloc_func alloc_func,
         free_func free_func,
         void* opaque) const noexcept = 0;
 
+    /** Destroy a decoder instance.
+        @param state The decoder state to destroy.
+    */
     virtual void
     destroy_instance(decoder_state* state) const noexcept = 0;
 
+    /** Decompress data in one call.
+        @param encoded_size Input data size.
+        @param encoded_buffer Input data buffer.
+        @param decoded_size Pointer to variable receiving output size.
+        @param decoded_buffer Output buffer.
+        @return Result code indicating success or failure.
+    */
     virtual decoder_result
     decompress(
         std::size_t encoded_size,
         const std::uint8_t encoded_buffer[],
         std::size_t* decoded_size,
         std::uint8_t decoded_buffer[]) const noexcept = 0;
 
+    /** Decompress data in streaming mode.
+        @param state The decoder state.
+        @param available_in Pointer to input bytes available.
+        @param next_in Pointer to pointer to input data.
+        @param available_out Pointer to output space available.
+        @param next_out Pointer to pointer to output buffer.
+        @param total_out Pointer to variable receiving total bytes written.
+        @return Result code indicating decoder state.
+    */
     virtual decoder_result
     decompress_stream(
         decoder_state* state,
@@ -79,24 +176,52 @@ struct BOOST_SYMBOL_VISIBLE
         std::uint8_t** next_out,
         std::size_t* total_out) const noexcept = 0;
 
+    /** Check if more output is available.
+        @param state The decoder state.
+        @return True if output is available, false otherwise.
+    */
     virtual bool
     has_more_output(const decoder_state* state) const noexcept = 0;
 
+    /** Return buffered output data.
+        @param state The decoder state.
+        @param size Pointer to variable receiving output size.
+        @return Pointer to output buffer.
+    */
     virtual const std::uint8_t*
     take_output(decoder_state* state, std::size_t* size) const noexcept = 0;
 
+    /** Check if decoder has been used.
+        @param state The decoder state.
+        @return True if decoder has processed data, false otherwise.
+    */
     virtual bool
     is_used(const decoder_state* state) const noexcept = 0;
 
+    /** Check if decompression is finished.
+        @param state The decoder state.
+        @return True if decompression is complete, false otherwise.
+    */
     virtual bool
     is_finished(const decoder_state* state) const noexcept = 0;
 
+    /** Return the error code from the decoder.
+        @param state The decoder state.
+        @return The error code.
+    */
     virtual error
     get_error_code(const decoder_state* state) const noexcept = 0;
 
+    /** Return a string description of an error code.
+        @param c The error code.
+        @return Pointer to error description string.
+    */
     virtual const char*
     error_string(error c) const noexcept = 0;
 
+    /** Return the Brotli library version.
+        @return Version number.
+    */
     virtual std::uint32_t
     version() const noexcept = 0;
 
@@ -117,6 +242,10 @@ struct BOOST_SYMBOL_VISIBLE
 #endif
 };
 
+/** Install the decode service into a polystore.
+    @param ctx The polystore to install the service into.
+    @return A reference to the installed decode service.
+*/
 BOOST_CAPY_DECL
 decode_service&
 install_decode_service(polystore& ctx);