Switch index format from HTML to EJS to match upstream changes

[meltyshev]

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• I have read the contributing guideline and understand that I have made the correct modifications

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Description:

Update Dockerfiles to build the client with INDEX_FORMAT=ejs and move the resulting index.ejs to /app/views/ instead of using index.html. This matches the upstream PLANKA change and resolves the reported issue (plankanban/planka#1593).

Benefits of this PR and context:

Upstream PLANKA switched the client index format from HTML to EJS (plankanban/planka#1451). Without this change, the app is completely broken because the server tries to load index.ejs instead of index.html, which always results in a 500 error.

How Has This Been Tested?

Verified that the changes in both Dockerfile and Dockerfile.aarch64 are consistent. Built the image and checked that all files are placed in the correct location.

Source / References:

• PR with the related changes: feat: add support for custom URL paths via BASE_URL configuration plankanban/planka#1451
• Reported issue in PLANKA: [Bug]: Planka showing 500 after latest docker-release plankanban/planka#1593

[github-actions]

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[LinuxServer-CI]

I am a bot, here is the pushed image/manifest for this PR:

ghcr.io/linuxserver/lspipepr-planka:v2.1.0-pkg-642512ea-dev-c251caef0a4999d7ec044f1563c9a4dabc8a753a-pr-14

[thespad]

Thanks for this.