feat(egfx): add ClearCodec client-side decode dispatch

[Greg Lamberson (glamberson)]

Follow-up to #1174.

Wires ClearCodec into the EGFX client's WireToSurface1 codec dispatch,
matching the existing AVC420 and Uncompressed decode patterns.

Changes:

• ClearCodecDecoder field on GraphicsPipelineClient (always enabled,
  pure Rust, no external codec dependency)
• Codec1Type::ClearCodec arm decodes bitmap data and converts BGRA
  output to RGBA for the uniform BitmapUpdate pixel format
• Decoder caches (V-bar, glyph) reset on ResetGraphics
• 3 integration tests (basic decode, RGBA output verification,
  reset/re-decode cycle)
• 1 unit test for BGRA-to-RGBA channel reordering

Unlike H.264 which requires an external decoder via the H264Decoder
trait, ClearCodec is pure Rust (ironrdp-graphics) and initialized
unconditionally.

[Copilot]

Pull request overview

This PR introduces ClearCodec support across the stack (PDU parsing, graphics encode/decode, and EGFX client/server integration) and adds a comprehensive test suite to validate correctness and resilience.

Changes:

• Added ClearCodec PDU parsing modules (residual, bands, subcodec, RLEX) under ironrdp-pdu.
• Implemented ClearCodecDecoder/ClearCodecEncoder (with glyph/V-bar caching) under ironrdp-graphics.
• Integrated ClearCodec handling into EGFX client decode path and EGFX server frame queuing; added new tests in testsuite-core.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
crates/ironrdp-testsuite-core/tests/graphics/mod.rs	Registers the new ClearCodec graphics test module.
crates/ironrdp-testsuite-core/tests/graphics/clearcodec.rs	Adds extensive round-trip and adversarial ClearCodec tests.
crates/ironrdp-testsuite-core/tests/egfx/client.rs	Adds EGFX pipeline tests for ClearCodec processing/reset behavior.
crates/ironrdp-pdu/src/codecs/mod.rs	Exposes the new ClearCodec codec module in the PDU crate.
crates/ironrdp-pdu/src/codecs/clearcodec/mod.rs	Implements ClearCodec bitmap stream + composite payload decoding.
crates/ironrdp-pdu/src/codecs/clearcodec/residual.rs	Implements residual layer (BGR RLE) encode/decode helpers.
crates/ironrdp-pdu/src/codecs/clearcodec/bands.rs	Implements bands layer decoding (V-bar structures).
crates/ironrdp-pdu/src/codecs/clearcodec/subcodec.rs	Implements subcodec layer decoding for regions.
crates/ironrdp-pdu/src/codecs/clearcodec/rlex.rs	Implements RLEX subcodec decoding.
crates/ironrdp-graphics/src/lib.rs	Exposes ironrdp_graphics::clearcodec.
crates/ironrdp-graphics/src/clearcodec/mod.rs	Adds ClearCodec encoder/decoder and decode compositing pipeline.
crates/ironrdp-graphics/src/clearcodec/glyph_cache.rs	Implements glyph cache storage for ClearCodec.
crates/ironrdp-graphics/src/clearcodec/vbar_cache.rs	Implements V-bar cache storage and reconstruction for bands.
crates/ironrdp-egfx/src/server.rs	Adds a send_clearcodec_frame helper to enqueue ClearCodec frames.
crates/ironrdp-egfx/src/client.rs	Adds ClearCodec decode path and BGRA→RGBA conversion for bitmap updates.

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[Copilot]

Pull request overview

Adds client-side ClearCodec decode support to EGFX by wiring a persistent ClearCodec decoder into WireToSurface1 codec dispatch and normalizing output pixels to the existing RGBA BitmapUpdate format.

Changes:

• Add ClearCodec decode path in GraphicsPipelineClient (including BGRA→RGBA conversion and reset behavior on ResetGraphics).
• Introduce/extend ClearCodec wire-format parsing in ironrdp-pdu and codec implementation (decoder/encoder + caches) in ironrdp-graphics.
• Add integration/unit tests covering decode dispatch, pixel format conversion, cache/reset behavior, and adversarial inputs.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
crates/ironrdp-egfx/src/client.rs	Adds ClearCodec decoder to client dispatch, resets state on ResetGraphics, and converts BGRA output to RGBA BitmapUpdate.
crates/ironrdp-egfx/src/server.rs	Adds send_clearcodec_frame() helper for emitting ClearCodec WireToSurface1 frames.
crates/ironrdp-graphics/src/lib.rs	Exposes the new clearcodec module.
crates/ironrdp-graphics/src/clearcodec/mod.rs	Implements ClearCodec decoder/encoder and composite layer application (residual/bands/subcodecs).
crates/ironrdp-graphics/src/clearcodec/glyph_cache.rs	Introduces glyph cache storage for ClearCodec glyph hits.
crates/ironrdp-graphics/src/clearcodec/vbar_cache.rs	Adds V-bar and short V-bar ring-buffer cache implementation used by bands layer.
crates/ironrdp-pdu/src/codecs/mod.rs	Exports the ClearCodec wire-format module.
crates/ironrdp-pdu/src/codecs/clearcodec/mod.rs	Defines ClearCodec stream/container structures, flags, and composite payload parsing.
crates/ironrdp-pdu/src/codecs/clearcodec/residual.rs	Adds residual layer (BGR RLE) decode/encode helpers.
crates/ironrdp-pdu/src/codecs/clearcodec/bands.rs	Adds bands layer parsing (V-bar references and inline short V-bar misses).
crates/ironrdp-pdu/src/codecs/clearcodec/subcodec.rs	Adds subcodec layer region parsing (raw/NSCodec/RLEX).
crates/ironrdp-pdu/src/codecs/clearcodec/rlex.rs	Adds RLEX subcodec decoding (palette + packed run/suite segments).
crates/ironrdp-testsuite-core/tests/graphics/mod.rs	Registers the new ClearCodec graphics tests module.
crates/ironrdp-testsuite-core/tests/graphics/clearcodec.rs	Adds ClearCodec codec-level integration tests (round-trip, adversarial inputs, cache/session behavior).
crates/ironrdp-testsuite-core/tests/egfx/client.rs	Adds EGFX client integration tests for ClearCodec dispatch, RGBA output verification, and reset/re-decode cycle.

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