Add GPU driver integration for v1.6.0

[PrimeBuild-pc]

Adds GPU vendor detection, NVIDIA driver FPS cap via NvAPIWrapper, NVIDIA Digital Vibrance support, AMD color management status, GPU driver UI polish, documentation updates, Codecov coverage upload, and version metadata for v1.6.0.

AMD Radeon Chill is intentionally not shown because no safe runtime integration is currently available. G-Sync and FreeSync are shown only as unsupported/read-only status where appropriate.

Validation:

• dotnet build --configuration Release passed
• dotnet test --configuration Release passed: 165 tests
• UI manually checked on AMD system
• app.manifest remains asInvoker
• winget/choco untouched
• release artifacts untouched

[PrimeBuild-pc]

Review focus before merging:

1. Confirm CI and Codecov

• Build/test workflow passes on GitHub Actions.
• Codecov receives the Cobertura report and no longer shows 0%.
• README badge points to the correct branch/repo.

2. Confirm versioning

• App reports 1.6.0 consistently.
• No winget/choco/release artifacts were changed in this PR.
• Release packaging will be handled separately after merge.

3. Confirm GPU driver behavior

• NVIDIA FPS cap never writes to the global driver profile silently.
• FPS cap requires a valid target application path.
• NVIDIA DRS writes are persisted only when the user explicitly applies or clears the cap.
• NVIDIA Digital Vibrance is clearly scoped to the primary NVIDIA display.
• AMD Radeon Chill is intentionally not shown.
• G-Sync / FreeSync are read-only/unsupported statuses only, not fake toggles.

4. Confirm UI/UX

• Settings tab order is correct.
• Frame Cap Assistant is under GPU Driver.
• Color management / Digital Vibrance status is under Display Settings.
• Unsupported controls are disabled and explain why through text/tooltips.
• Reset glyphs render correctly and no mojibake remains.

5. Regression checks

• Crosshair still appears.
• FPS overlay still works.
• Settings load/save works.
• Profiles work.
• app.manifest remains asInvoker.
• App starts safely on unsupported GPU / missing vendor API environments.

Manual AMD validation completed locally:

• AMD Radeon RX 6950 XT detected correctly.
• AMD Color Management shown as supported.
• NVIDIA-only controls are disabled as expected.
• UI glyph corruption fixed.
• Build and tests passed locally: 165 tests.