Generate release changelog entries from git diff and align v0.4.7 notes with actual changes

[Copilot]

Release notes were being generated with a generic placeholder instead of the real delta between commits. This updates the release flow to derive CHANGELOG.md entries from git diff output and refreshes the existing 0.4.7 entry to reflect actual file-level changes.

• Release workflow: derive changelog content from commit delta

  • Reordered release steps so version bump + badge updates happen before changelog generation.
  • Replaced static changelog text with dynamic lines built from git diff --name-status HEAD.
  • Maps git status codes (A/M/D/R/C) to readable changelog verbs.
  • Excludes CHANGELOG.md from generated lines to avoid self-referential entries.
  • Fails fast when no release-file changes are detected; logs unknown status codes as warnings.

• Changelog: update latest release entry

  • Revised 0.4.7 section to document the concrete changes from the previous release commit:
    • version bump in cli/__version__.py
    • version badge updates in README.md and hugo-docs/content/_index.md

# release.yml (changelog generation)
diff_output = subprocess.check_output(
    ["git", "diff", "--name-status", "HEAD"], text=True
).strip()

if file_path == "CHANGELOG.md":
    continue

changes.append(f"- {status_label} `{file_path}`.")