chore: release v1.16.4

[EhabY]

Release v1.16.4: bumps package.json to 1.16.4 and cuts the changelog's Unreleased section as the v1.16.4 release.

Changes

• package.json: version 1.16.3 → 1.16.4
• CHANGELOG.md: ## Unreleased → ## [v1.16.4](https://github.com/coder/vscode-coder/releases/tag/v1.16.4) 2026-09-23
• CHANGELOG.md: adds the missing Fixed entry for the CLI progress-log cleanup (fix(cli): await trailing progress-log writes before settling download #1122)

Changelog audit (v1.16.3...main)

PR	Changelog
#1100 connection log buffer	Added coder.connectionLogBuffer.size, Fixed unrecoverable WebSocket closes
#1110 Windows SSH config permissions	Fixed
#1115 updates as one build	Fixed (one build, update-failure prompt, Tasks before 2.29)
#1122 CLI progress log	Fixed (added in this PR)
#1116, #1117, #1123, #1124	None: dependency bumps, lint tooling, and packages/ui, which nothing ships yet

Notes

• The release tag must point at a commit where package.json reads 1.16.4. release.yaml validates the tag against package.json and requires it to be an ancestor of origin/main.