docs: update changelog for v0.25.2

[augmentmoogi]

Update the changelog with release notes for v0.25.2.

• Add new feature notes for typed custom webhooks in GitLab and Jira integrations and configurable chat placeholder text in expert configs
• Document improvements to injected prompt branding and backward compatibility via the deprecated --no-tui alias
• Capture bug fixes for daemon auth consistency, headless cloud expert prompt rendering, and noisy daemon setup logs

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[augmentmoogi]

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