release: v0.51.0 — damage overlay + TT advance cache (#491)

* feat: migrate ggcanvas to DamageReporter API (ADR-065 + ADR-066)

- DamageRectSetter → DamageReporter via RegisterDamageSource('gg')
- damage_debug.go → implements DamageOverlayRenderer with text labels
- Per-source colors, anti-aliased borders, reason detail in labels
- 67 ggcanvas tests passing

Part of: #437

* docs: GOGPU_DEBUG_DAMAGE=1 → =overlay (pre-v1.0 clean cut)

* perf(text): TT advance cache + deps bump + examples update (#490)

- Per-(ppem, glyphID) advance cache in ttHintCacheEntry avoids
  re-running TT bytecode interpreter for advance-only queries.
  60fps→15fps regression from v0.50.13 advanceResolver fixed.
- deps: gpucontext v0.26.0, wgpu v0.31.0, gogpu v0.51.0
- examples: migrate LoadFontFace to text.NewFontSourceFromFile API
- multi_damage_demo: single-path spinner, FPS counter, proper overlay

* fix(lint): remove unused const, fix staticcheck SA4023 in overlay test

fix(text): variable font advance + shear aliased rendering (#405) (#489)

* fix(text): variable font advance + shear aliased rendering (#405)

Two fixes for variable font regression reported by @tsl0922:

1. drawGlyphsVariable used TT-hinted phantom advances (integer-rounded)
   for positioning while Face.Advance/MeasureString used HVAR (fractional).
   Now uses HVAR via varOrRawAdvance(), matching FreeType ttgload.c:964-977.
   Also fixed faceGlyphAdvance to use advanceResolver for MultiFace/FilteredFace.

2. Aliased text with shear/rotation produced garbled output because
   NoAAFiller cannot handle non-axis-aligned paths. Now forces AA for
   non-axis-aligned outlines in both drawStringCPUAliased and drawStringCPU,
   matching Skia computeAxisAlignmentForHText pattern.

8 new tests covering advance consistency and shear rendering quality.

* fix(test): skip ink-width assertion when font lacks test glyphs

Cantarell VF trimmed has no Latin glyphs — rightmostInk=-1 on CI.
Skip subtest instead of failing with impossible -50px width.

Merge branch 'main' of https://github.com/gogpu/gg

Merge branch 'main' of https://github.com/gogpu/gg

Merge branch 'main' of https://github.com/gogpu/gg

Merge branch 'main' of https://github.com/gogpu/gg

chore: prepare v0.50.11 release — deps + docs for #466-469 (#471)

* chore: prepare v0.50.11 — gogpu v0.48.3, CHANGELOG/README/ROADMAP for #466-469

* chore: update gogpu v0.48.4, finalize v0.50.11

fix(gpu): bind group lifecycle + deps v0.30.29 + examples update (#460)

* fix(gpu): defer bind group release for shared encoder (ADR-056, #287)

Shared encoder path released bind groups before gogpu submitted,
causing use-after-free. Own-encoder path unaffected (submit before
return). Fix: defer release to BeginFrame() for shared encoder,
matching Skia Graphite frame-scoped resource lifecycle.

Tested: Vulkan 2314+ frames, DX12, GLES — all 60 FPS stable.

* fix(gpu): defer bind group release for shared encoder + update examples

Shared encoder path released bind groups before submit, causing
use-after-free (wgpu#287). Defer to BeginFrame() for shared encoder.
Update all 14 examples to latest ecosystem deps. Remove stale replace
directives.

chore: prepare release v0.50.9 (#459)

release: v0.50.8 — dual fill/stroke, blend modes, shaper HVAR, ScaleA…

…bout (#438, #442, #405) (#443)

* feat: ScaleAbout, ShearAbout, undeprecate LoadFontFace, README patterns (#442)

- ScaleAbout(sx, sy, x, y) and ShearAbout — API symmetry with RotateAbout
- LoadFontFace undeprecated — convenient one-liner for quick start
- README: Common Patterns section (FillPreserve+Stroke, Clear, fonts, transforms)
- 5 enterprise tests for ScaleAbout/ShearAbout (pixel-exact match vs manual)

Addresses root.cz tutorial feedback by @tisnik.

* chore: update deps — wgpu v0.30.23, naga v0.17.16, goffi v0.6.2

* fix: shaper HVAR advances for variable fonts (#405)

OwnShaper and BuiltinShaper used hmtx-only advances (base weight),
while ExtractOutlineHintedVar (ADR-054) applied gvar deltas to outlines.
Wider bold glyphs positioned at narrower base-weight spacing caused
letters to overlap under shear/rotation.

Fix: buildShapedGlyphs uses GlyphAdvanceVar (HVAR-adjusted) when face
has variations, matching skrifa invariant: advance_source == outline_source.

Reported by @tsl0922: 'r' and 'l' merge in 'hello world' with shear.

* feat: separate fill and stroke brushes + Push/Pop paint save (#438)

SetFillBrush and SetStrokeBrush are now genuinely independent, matching
HTML5 Canvas fillStyle/strokeStyle semantics. Previously aliased to same
brush. SetColor/SetRGB/SetHexColor set both (backward compat).

Paint uses brushState struct for each side with explicit FillColorAt/
StrokeColorAt methods. SoftwareRenderer and GPU pipeline route fill/stroke
to correct brush via strokeMode flag.

Push/Pop now saves and restores paint state (fill brush, stroke brush,
blend mode) matching Cairo cairo_save/Canvas ctx.save.

ADR-055. 8 dual-paint enterprise tests + 9 agent tests.
Performance: -40% faster FillRect (brushState inlining more cache-friendly).

* chore: prepare release v0.50.8