docs: changelog for v0.5.4

[dpup]

Summary

Cut v0.5.4 from Unreleased. Three Claude Code fixes:

• TUI freeze on first paint with Claude Code 2.1.150+ (fix(tui): drain vt emulator reply pipe to prevent compositor deadlock #362)
• Container session directory diverging from host on workspaces with . or _ (fix(claude): match Claude Code's project-dir slug rule #364)
• Marketplace plugin hook scripts losing the executable bit (fix(claude): preserve source file mode in marketplace tar #363)

#361 (CI Node 24 bump) is internal-only and intentionally not in the release notes.

Test plan

• CHANGELOG renders correctly with new v0.5.4 section
• Merge, then tag v0.5.4 from main to trigger the goreleaser workflow

[claude]

Claude finished @dpup's task in 1m 11s —— View job

---

Code Review

• Gather context
• Read CHANGELOG.md diff
• Check against docs/STYLE-GUIDE.md
• Post review findings

---

Changelog entry looks solid. Structure is correct: ## Unreleased is empty (ready for the next cycle), the ## v0.5.4 section immediately follows with the summary paragraph and ### Fixed entries, all three entries follow the "Fix X — previously, Y happened when Z" pattern from CLAUDE.md, and every entry has a PR link. Voice is active, language is factual and specific throughout.

One minor inaccuracy to consider:

Summary paragraph vs. detailed entry — "space" is omitted

The summary says:

workspaces with . or _ in the path

The detailed entry says (correctly):

For any workspace path containing a ., _, or space (e.g. a macOS username like user.name)

The summary silently drops "or space" from the affected character set. Since anyone scanning the summary to decide if they're affected would miss the space case, it's worth adding for accuracy.

Suggested fix: Fix this →

Everything else looks good to merge.