feat(lint+autofix): default glob covers YAML+JSON, not just markdown

[topcoder1]

Summary

Broadens the default `markdown_glob` from `/*.md` to `/*.{md,yml,yaml,json}` in both `lint.yml` and `prettier-autofix.yml`. Repos get the same prettier-check + autofix loop on YAML config, package.json, etc. TS/JS source intentionally excluded — those are more contentious and belong to a separate opt-in.

Bug fix bundled

`compgen -G` does pathname expansion (incl. globstar ``) but NOT brace expansion. With the new brace-pattern default, the existing target-resolution would have matched zero files. Added an `expand_braces` helper that splits `/*.{md,yml,yaml,json}` into individual globs, runs compgen against each, and unions the results.

Verified locally:
```
expand_braces "/*.{md,yml,yaml,json}" → 4 lines
expand_braces "/.md" → 1 line (no-op)
expand_braces "src/**/.{ts,tsx}" → 2 lines
```

Backward compatibility

• Input name stays `markdown_glob` — callers that override don't break.
• `changed_only: true` (default) means baseline YAML/JSON drift in repos isn't rewritten until a PR happens to touch those files.
• Repos that want to opt out specific files can add them to `.prettierignore`.

Test plan

• actionlint clean
• brace-expansion helper unit-tested
• After merge: every fleet repo with autofix wired (40 + finsight) gets the broader scope on the next PR

🤖 Generated with Claude Code

[claude]

Bug: two-brace-group globs produce silently wrong output.

suffix is computed with ##*\} (strip to the last }), and prefix with %%\{* (strip from the first {). For the default single-group pattern (**/*.{md,yml,yaml,json}) this is fine. But a user override like {src,lib}/**/*.{ts,tsx} yields:

variable	value
prefix	"" (whole string consumed — starts with {)
suffix	"" (whole string consumed — ends with })
middle	"src,lib"
output	src, lib ← bare directory names, not valid globs

compgen -G "src" matches a file/dir literally named src, not src/**/*.ts. Prettier silently processes zero matching files (or the wrong ones) with no error.

Fix: strip to the first } for suffix, then recurse (or loop) to expand any remaining brace groups in that suffix:

Suggested change

	local suffix="${pat##*\}}"
	local suffix="${pat#*\}}"

With this change, {src,lib}/**/*.{ts,tsx} → suffix /**/*.{ts,tsx}, output src/**/*.{ts,tsx} / lib/**/*.{ts,tsx}. A second pass through expand_braces (or a recursive call) is then needed to expand the remaining group — or document that only a single brace group is supported and add an [[ "$suffix" == *\{*\}* ]] guard that exits non-zero with a clear error.

[claude]

Same two-brace-group bug as in lint.yml line 263 — suffix="${pat##*\}}" strips to the last }, so a user-provided glob like {src,lib}/**/*.{ts,tsx} silently emits bare src / lib with no path or extension. See the comment on the lint.yml copy for the full analysis and suggested fix.

[claude]

Flagged 1 issue inline (duplicated in both workflow files): expand_braces uses ##*\} for suffix, which silently breaks any user-supplied glob with two brace groups (e.g. {src,lib}/**/*.{ts,tsx}) — emitting bare directory names instead of valid globs. Default single-group glob is unaffected.