Add sprites sample

[jonathanpeppers]

Summary

Implements the 8bitworkshop sprites.c demo - 32 hardware sprites bouncing around the screen with random velocities.

Reduced from 64 to 32 actors because 4 arrays x 64 bytes = 256 bytes exceeds the NES zero-page local memory available.

APIs used

pal_all, oam_clear, oam_spr (5 params with return value), oam_hide_rest, ppu_on_all, ppu_wait_frame, rand8().
All patterns already supported - no transpiler changes needed.

Testing

All 168 tests pass (166 existing + 2 new).

[Copilot]

Pull request overview

Adds a new sprites sample (based on the 8bitworkshop sprites.c demo) to the dotnes repo, and wires it into the existing snapshot-based transpiler test suite and sample documentation.

Changes:

• Adds samples/sprites (C# implementation + CHR data + csproj) and registers it in samples/samples.sln.
• Adds new test inputs (sprites.debug.dll / sprites.release.dll) and a new verified ROM snapshot for TranspilerTests.Write.sprites.
• Updates docs/8bitworkshop-samples.md to mark sprites.c as implemented.

Reviewed changes

Copilot reviewed 7 out of 10 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
src/dotnes.tests/TranspilerTests.cs	Adds sprites to the snapshot test matrix (debug + release).
src/dotnes.tests/TranspilerTests.Write.sprites.verified.bin	New expected ROM output snapshot for the sprites sample.
src/dotnes.tests/Data/sprites.release.dll	New release-mode test input DLL for transpilation.
src/dotnes.tests/Data/sprites.debug.dll	New debug-mode test input DLL for transpilation.
samples/sprites/sprites.csproj	New sample project definition for sprites.
samples/sprites/sprites.c	Reference C source for the original demo being ported.
samples/sprites/chr_generic.s	CHR ROM data used by the sample.
samples/sprites/Program.cs	C# top-level program implementing the sprites sample behavior.
samples/samples.sln	Registers the new sprites sample project in the samples solution.
docs/8bitworkshop-samples.md	Moves sprites.c into “Already Implemented” and documents required APIs.