docs(mix): repair broken and stale links

[leoafarias]

Related issue

None.

Description

I audited every external URL in the repository (95 unique links, excluding lockfiles and templates) by actually requesting each one, and fixed the results that were broken or resolving through redirect chains.

Broken links (404)

Location	Was	Now
packages/mix_lint/README.md	github.com/virtuallyio/mix	github.com/btwld/mix
packages/mix/test/src/core/nested_style_variant_test.dart	github.com/btwld/remix/issues/59	github.com/conceptadev/remix/issues/59
packages/mix/CHANGELOG.md	github.com/leoafarias/mix/issues/59	github.com/conceptadev/mix/issues/59

The mix_lint one is user-facing on pub.dev. GitHub does not redirect issue paths for moved repositories, so those two had to use the canonical conceptadev names — see the open question below.

Stale links

• Logo images and license badges in README.md, packages/mix/README.md, packages/mix_annotations/README.md, and packages/mix_generator/README.md were served from raw.githubusercontent.com/leoafarias/mix — a personal fork. The pub.dev listings for three published packages rendered their logo and licence badge from it. Now btwld/mix. (assets/dark.svg and assets/light.svg already exist in this repo.)
• fluttermix.com/docs/* took three redirects (/docs/* → /documentation/* → /documentation/mix/*, plus apex → www). All now point directly at https://www.fluttermix.com/documentation/mix/*, which resolves in zero hops. This includes the ecosystem link, which now targets the renamed mix-winds page.
• opensource.org/licenses/mit-license.php → opensource.org/license/mit and conventionalcommits.org → www.conventionalcommits.org, following their upstream canonical moves.

Exports generator fix

Regenerating with melos run exports on main adds export 'src/core/providers/focus_highlight_mode_provider.dart';, which fails analysis:

warning - lib/mix.dart:40:1 - The member 'FocusHighlightModeProvider' can't be exported
as a part of a package's public API - invalid_export_of_internal_element

FocusHighlightModeProvider is @internal, but it lives in src/core/providers/ and the generator's heuristic only skips src/internal/. It was added in #1006 and the barrel was never regenerated, so the drift was latent. Adding it to excludedPaths — alongside the existing documented exclusions — makes melos run exports idempotent and analysis-clean.

Deliberately untouched

• cdn.tailwindcss.com in example/real_tailwind/*.html — unpinned on purpose; pinning it would move the parity baselines.
• example/assets/fonts/roboto/OFL.txt — a verbatim upstream licence document.
• github.com/leoafarias in the plugin manifests — a personal profile link, correctly personal.
• github.com/orgs/btwld/projects/6 in add_to_ai_initiatives_board.yml — returns 404 anonymously, but org projects are private by default and my token lacks read:project, so I could not confirm either way. Left alone.

Open question (not addressed here)

Every github.com/btwld/* link in this repo resolves through one permanent redirect to github.com/conceptadev/* — the repositories are canonically under conceptadev, while btwld/mix-docs is canonically btwld. The same pattern holds across remix, ack, naked_ui, and rockets in the docs repo. That is ~19 links here and ~80 in mix-docs, and which direction is correct is a branding decision, so I left them as btwld and only used conceptadev where btwld genuinely 404s. Happy to normalize either way.

Validation

• Re-ran the full link check after the changes: no 404s remain except the unverifiable org-project URL and intentional templates.
• melos run exports — regenerates with no drift.
• fvm dart analyze in packages/mix — no issues (was 1 warning after regeneration).
• melos run analyze:dart — all packages clean.
• melos run ci — passed.
• dart format --set-exit-if-changed on all changed Dart files — 0 changed.