chore(deps): bump Biome to 2.5.13 across all five version pins

[sirjmann92]

Unblocks #85.

Why this exists

Dependabot's frontend-dependencies group PR (#85) bumps @biomejs/biome 2.5.12 → 2.5.13, but Dependabot can only reach frontend/package.json and frontend/package-lock.json. The other three pins stay at 2.5.12, so check-biome-pins fails:

Biome version pins disagree with frontend/package.json (2.5.13):

  .pre-commit-config.yaml (rev): 2.5.12
  .pre-commit-config.yaml (additional_dependencies): 2.5.12
  biome.json ($schema): 2.5.12

This is the documented first-run-after-a-bump failure, working as designed — the hook exists precisely to make that divergence loud rather than silent.

Why the fix lives here and not on #85

scripts/check_biome_pins.py treats frontend/package.json as the source of truth, so a branch that bumped only the three lagging pins would fail the same check in the opposite direction. The Biome bump therefore has to happen completely or not at all.

Doing it here keeps #85 untouched — no maintainer push to a Dependabot branch, which would stop Dependabot from managing it. Once this merges, #85 rebases with its Biome change reduced to a no-op and its other three updates (daisyui 5.7.28 → 5.7.37, @types/node, vite 8.2.2 → 8.3.0) intact.

What changed

All five pins, together:

Location	2.5.12 → 2.5.13
frontend/package.json	@biomejs/biome
frontend/package-lock.json	resolved entry + 8 platform CLI binaries
.pre-commit-config.yaml	rev
.pre-commit-config.yaml	additional_dependencies
biome.json	$schema URL

The lockfile diff is Biome-only — verified that every changed resolved entry is under @biomejs/.

Verification

npm ci from a clean tree, then svelte-kit sync, then pre-commit run --all-files: all 16 hooks pass, biome check included.

Being a patch bump, there is no ruleset churn — nothing to reformat, so none of the review burden that AGENTS.md warns about for multi-release jumps.