Shaders: fingerprint without node positions, compile counter hook; 760 checks (#65)

Development.md

@@ -12,7 +12,7 @@ npm run check        # typecheck + lint + format:check + tests, the gate CI runs
                      #   code is lost (tail's is reported), so a red run reads as green
 npm run build        # writes dist/ and regenerates index.html
 ./build.sh           # the same under `set -o pipefail`, for callers that pipe the output
-node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 758 editor checks, screenshots in /tmp/gm-e2e-*.png
+node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 760 editor checks, screenshots in /tmp/gm-e2e-*.png
 GM_STEPS=20 node tools/e2e.mjs                                # or 1-12, or 6,20 — a subset while working on one step
 ./e2e.sh start [GM_STEPS]                                     # the same run detached, see below
 ./e2e.sh status                                               # live progress, or the last run's result
@@ -151,4 +151,4 @@ widths to find click points. The **render device is not in this repo** — `/dev
 and a 1 GB `/dev/shm` come from `container.options` in the runner's own `config.yaml`, which
 applies to every job on that runner. Without them chromium falls back to llvmpipe, which gets
 WebGL 1.0 only. Measured in the job container: `ANGLE (Intel, Vulkan 1.3.230, HD Graphics 630)`,
-WebGL 2.0, and the same 758 checks as here.
+WebGL 2.0, and the same 760 checks as here.

Shaders.md

@@ -150,7 +150,10 @@ quad has four corners and stays a quad (#79 is the vertex-side step that would c
 fragment (every node reachable from the Output becomes one local per output, in dependency order;
 every Property a `uniform float u_<name>`), `src/viewport/shaders.ts` wraps the result in a Pixi
 `Shader` for the sprite's mesh (`GraphShader`, with a vertex stage of its own) and
-`src/viewport/ShaderLibrary.ts` caches the compiled graph per asset. A sprite's picture is a `Mesh`
+`src/viewport/ShaderLibrary.ts` caches the compiled graph per asset, keyed by a fingerprint of what
+the fragment depends on — node ids, types, params, declared ports, and which port feeds which — so
+moving, collapsing or folding compiles nothing again; a changed param or link does, once
+(`__gm.shaderCompiles()` counts it for the checks). A sprite's picture is a `Mesh`
 (a unit quad sized by its scale, `symbols.ts`), a sibling of the sprite's `Graphics` node under the
 same parent: Pixi 8 lets only plain containers have children, and the node keeps just the hit area.
 Two Pixi facts the code leans on: a mesh's texture is bound only for Pixi's own shader, so