fix: use textureSize instead of u_resolution for texel size in blur/sharpen shaders

[jtydhr88]

Preview renders at a clamped resolution (max 1024px), so u_resolution holds the preview dimensions, not the actual image dimensions. This caused blur radius and sharpen kernel offsets to scale incorrectly, producing visibly different results between preview and backend output.

Switch to textureSize(u_image0, 0) which reflects the actual input texture dimensions regardless of render target size, consistent with how Edge-Preserving Blur already handles this correctly.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

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Review profile: CHILL

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Run ID: 1b008f21-d9e8-4d9f-b02e-0741e51bef52

📥 Commits

Reviewing files that changed from the base of the PR and between cf44161 and eccd7c1.

📒 Files selected for processing (8)

• blueprints/.glsl/Glow_30.frag
• blueprints/.glsl/Image_Blur_1.frag
• blueprints/.glsl/Sharpen_23.frag
• blueprints/.glsl/Unsharp_Mask_26.frag
• blueprints/Glow.json
• blueprints/Image Blur.json
• blueprints/Sharpen.json
• blueprints/Unsharp Mask.json

✅ Files skipped from review due to trivial changes (1)

• blueprints/.glsl/Unsharp_Mask_26.frag

🚧 Files skipped from review as they are similar to previous changes (5)

• blueprints/.glsl/Sharpen_23.frag
• blueprints/.glsl/Image_Blur_1.frag
• blueprints/Sharpen.json
• blueprints/Image Blur.json
• blueprints/Unsharp Mask.json

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📝 Walkthrough

Walkthrough

This PR updates several fragment shaders (GLSL files and embedded shader strings in JSON blueprints) for Image Blur, Sharpen, Unsharp Mask, and Glow. Each change removes the u_resolution uniform and replaces 1.0 / u_resolution with 1.0 / vec2(textureSize(u_image0, 0)) to compute per-texel sampling offsets from the bound input texture.

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and specifically describes the main change: replacing u_resolution with textureSize for texel size calculations in blur/sharpen shaders.
Description check	✅ Passed	The description is directly related to the changeset, explaining the motivation (preview resolution vs actual image dimensions) and the solution (switching to textureSize).
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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[pythongosssss]

Looks like the Glow frag also has the same issue on line 78

[pythongosssss]

lgtm