Switch to @tailwindcss/vite + pin vite^7 to unbreak Docker build

[elemdos]

Summary

Docker image build has been broken for ~11 days; CI's main.yml fails at vite --config app.config.js build. Two vite 8 bugs are involved:

1. postcss-import bare specifier resolution — vite 8's bundled postcss-import tries to read <projectRoot>/tailwindcss as a literal path instead of resolving @import 'tailwindcss'; from node_modules, producing ENOENT: no such file or directory, open '/app/tailwindcss'.
2. lightningcss minify regression on Svelte scoped CSS — vite 8's default cssMinify is lightningcss, which rejects @keyframes blocks inside Svelte's nested-selector scoped CSS output.

Dependabot exposed both by bumping @sveltejs/kit 2.59.1 → 2.60.1, which let the transitive vite-plugin-svelte re-resolve from 6.x → 7.1.2 and pull in vite 8.

Fix

• Replace @tailwindcss/postcss with @tailwindcss/vite (the canonical Tailwind v4 + Vite setup) so the Tailwind entry is resolved by Tailwind's own plugin and never touches vite's broken postcss-import.
• Delete postcss.config.cjs (only contained the now-removed @tailwindcss/postcss entry; the postcss + postcss-nested deps are still used by runtime CSS workers, untouched).
• Add npm overrides pinning vite ^7.3.3 + @sveltejs/vite-plugin-svelte ^6.2.4 to sidestep the lightningcss minify regression. Both are within @sveltejs/kit 2.60.1's declared peer ranges.

Verified locally: npx vite --config app.config.js build succeeds, produces a ~230KB Tailwind CSS bundle plus Svelte component CSS chunks.

Test plan

• CI's main.yml workflow goes green on this branch
• ghcr.io/primocms/primo:main rebuilds and the testing deploy picks it up

Summary by CodeRabbit

• Chores
  • Switched Tailwind integration to the Vite plugin for improved compatibility and build performance.
  • Removed legacy PostCSS plugin configuration to simplify CSS processing.
  • Adjusted dev dependency set and locked build tool versions to ensure more consistent, reliable builds across environments.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 41841ad8-5497-4cdc-adab-49737e398f3d

📥 Commits

Reviewing files that changed from the base of the PR and between e2ef1d3 and 6583a84.

⛔ Files ignored due to path filters (1)

• package-lock.json is excluded by !**/package-lock.json

📒 Files selected for processing (3)

• app.config.js
• package.json
• postcss.config.cjs

💤 Files with no reviewable changes (1)

• postcss.config.cjs

🚧 Files skipped from review as they are similar to previous changes (2)

• package.json
• app.config.js

---

📝 Walkthrough

Walkthrough

This PR migrates Tailwind CSS from a PostCSS plugin to the Tailwind Vite plugin: package dependencies and overrides are updated, the Vite config imports and registers tailwindcss(), and the PostCSS plugin export is removed.

Changes

Tailwind Vite Plugin Migration

Layer / File(s)	Summary
Tailwind Vite dependency and version pins package.json	@tailwindcss/postcss is replaced with @tailwindcss/vite (^4.3.0), and overrides pins vite to ^7.3.3 and @sveltejs/vite-plugin-svelte to ^6.2.4.
Vite configuration with Tailwind plugin app.config.js	Adds import tailwindcss and registers tailwindcss() before sveltekit() in the Vite plugins array.

🎯 2 (Simple) | ⏱️ ~10 minutes

🐰 A small plugin hops in line,
Tailwind finds a Vite-shaped vine,
PostCSS waves a fond goodbye,
Build steps hum, and styles reply ✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main changes: switching to @tailwindcss/vite and pinning vite^7 to fix Docker build failures.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/vite8-tailwind-postcss-import

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}