chore(main): release cua-driver-rs 0.21.0

[cua-release-bot]

🤖 I have created a release beep boop

0.21.0 (2026-08-19)

Features

• cua-driver: extend Project Centennial across desktop platforms (#3189) (a744308)
• cua-driver: Project Centennial preview (#3188) (61e51cd)

Bug Fixes

• cua-driver: admit stable local history signatures (#3262) (4864ccd)
• cua-driver: attribute hosted Windows apps by window (#3227) (30d9130)
• cua-driver: drop the stale 0.17 version from element_index messages (e14891a)
• cua-driver: harden consented existing-profile attachment (#3211) (3f791b2)
• cua-driver: launch isolated browser without pid (#3208) (eaf5a34)
• cua-driver: preserve history admission on macOS relaunch (#3245) (9045b0c)
• cua-driver: refuse unproven Wayland window capture (#3200) (c78c1d8)
• cua-driver: strip UTF-8 BOM from uninstall.ps1 (da44420), closes #3174
• cua-driver: tell operators to reconnect agent sessions after history enable (#3224) (62ede45), closes #3220
• cua-driver: tolerate missing local autostart task (#3229) (f913244)

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[cua-release-bot]

🤖 Created releases:

• cua-driver-rs-v0.21.0

🌻