fix(docs): expose NEXT_PUBLIC_BASE_PATH so blueprint sample fetch works on GitHub Pages

[solidsnakedev]

Problem

The "Load Sample" button on the Blueprint Codegen tool was returning "Failed to load sample blueprint" on the GitHub Pages deployment.

loadSample() fetched ${process.env.NEXT_PUBLIC_BASE_PATH ?? ""}/sample-blueprint.json, but NEXT_PUBLIC_BASE_PATH was never set, so it always resolved to /sample-blueprint.json — a 404 on GitHub Pages (where the site lives under /evolution-sdk/).

Fix

Extract basePath into a variable and expose it via env.NEXT_PUBLIC_BASE_PATH in next.config.mjs. Next.js bakes env.* values into the static export at build time, so the correct prefix (/evolution-sdk) is now available client-side.

History

1. Originally: fetch('/sample-blueprint.json') — worked locally, broken on GH Pages
2. Commit 2f2a6d5: hardcoded to /evolution-sdk/sample-blueprint.json — worked on GH Pages, broken locally
3. Later refactored to use NEXT_PUBLIC_BASE_PATH — correct pattern, but the env var was never injected
4. This PR: actually injects the env var

[Copilot]

Pull request overview

Fixes GitHub Pages deployment of the Blueprint Codegen “Load Sample” flow by ensuring the client-side fetch uses the correct base path during static export.

Changes:

• Introduce a shared basePath variable derived from GITHUB_ACTIONS.
• Reuse basePath for both basePath and assetPrefix.
• Expose NEXT_PUBLIC_BASE_PATH via next.config.mjs env so it’s baked into the static build.

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[Copilot]

Hardcoding '/evolution-sdk' makes the docs build fragile for repo renames and forks (GitHub Pages base path is typically /${repoName}). Consider deriving the base path from CI metadata (e.g., process.env.GITHUB_REPOSITORY → /${repoName}) and/or allowing an explicit override via an env var, then use that computed value for basePath, assetPrefix, and env.NEXT_PUBLIC_BASE_PATH.

Suggested change

	const basePath = isCI ? '/evolution-sdk' : ''
	const explicitBasePath = process.env.DOCS_BASE_PATH
	const inferredBasePath = process.env.GITHUB_REPOSITORY
	? `/${process.env.GITHUB_REPOSITORY.split('/').pop()}`
	: ''
	const basePath = explicitBasePath ?? (isCI ? inferredBasePath : '')

[Copilot]

Hardcoding '/evolution-sdk' makes the docs build fragile for repo renames and forks (GitHub Pages base path is typically /${repoName}). Consider deriving the base path from CI metadata (e.g., process.env.GITHUB_REPOSITORY → /${repoName}) and/or allowing an explicit override via an env var, then use that computed value for basePath, assetPrefix, and env.NEXT_PUBLIC_BASE_PATH.