fix(release): group multi-scope commits and exclude scoped types in changelog

[upsetbit]

Summary

The goreleaser changelog mis-categorized commits in the v0.26.0 release: the
headline fix(cli,server,store): honor remote device filters landed under
Others instead of Bug Fixes, and scoped docs(...)/chore(...)
commits leaked into the changelog instead of being excluded.

Two root causes in .goreleaser.yaml:

• Group regexps used [[:word:]-]+ for the commit scope, which does not
  match commas — so multi-scope commits like fix(cli,server,store): failed
  the Features/Bug Fixes patterns and fell through to Others. Single-scope
  commits (fix(panel):) matched fine, which is why prior releases looked
  correct.
• Exclude filters (^docs:, ^test:, ^chore:, ^ci:) matched only
  unscoped commits, so docs(proto):, chore(deps):, etc. were never
  excluded.

Changes

• Allow commas in the group scope class: [[:word:]-]+ → [[:word:],-]+.
• Match an optional scope in the exclude filters: ^docs: →
  ^docs(\([^)]+\))?!?: (and the same for test/chore/ci).

Validation

• goreleaser check — config is valid (the only reported issue is a
  pre-existing homebrew_casks.binary deprecation, unrelated to this change).
• Verified the grouping/exclude logic against the actual commit subjects
  using Go's regexp (the same RE2 engine goreleaser uses). All cases
  classify correctly: multi-scope fix(a,b,c): → Bug Fixes, single-scope
  still works, fix:/fix(a,b)!: handled, scoped docs/chore/ci/test
  excluded, merge commits excluded, refactor/perf → Others.

Affects future releases only; the v0.26.0 notes are already published and
unchanged.