Fix/internal buildable packages

[66HEX]

Description

I’ve sorted out the configuration of the internal packages:

1. $editor and $theme are now explicitly private,
2. theme uses the sources from the dev environment and from dist in production,
3. Nx caches the correct dist directories.

To be sure, I ran a benchmark on separate worktrees: 7 runs before the changes and 7 after. Previously, Nx reported a cache hit but didn’t restore any artifacts, and the production build failed every time (0/7). After the changes, the cache restores the entire dist, and the build succeeds on every attempt (7/7).

Checklist

• Add a changeset (not applicable - internal packages and Nx configuration only)

[changeset-bot]

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Latest commit: 92acb6d

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[glypse]

Hey, as you might notice I'm having a hard time resolving those conflicts. Could you please rebase your branch onto the latest main? Thanks in advance.

[glypse]

Thank you for your contribution!