v0.9.6 - web message edit polish

What's changed

• Polishes the web user-message editing UI with a more familiar compose-like edit surface.
• Replaces icon-only edit controls with clear Cancel and Send actions.
• Disables Send until there is a real edit while still supporting attachment-only edited messages.
• Fixes the accidental dark-mode textarea background inside the edit bubble.

Validation

• PR #57 Web E2E smoke passed before merge.
• Web E2E smoke passed on main after merge.
• dev was recreated from main and Web E2E smoke passed there too.
• App image published successfully for ghcr.io/yoloyash/overtchat-app:0.9.6 and latest.

Image

• ghcr.io/yoloyash/overtchat-app:0.9.6
• Digest: sha256:05c0147d0d022cb630a3b76070aa6d45704916946fd5703c2c952c411bf2f703
• Platforms: linux/amd64, linux/arm64