release: v0.5.21

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

fix: add marker guards for provider log line to pass Marker Guard CI

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

release: v0.5.19

release: v0.5.18

release: v0.5.17

release: v0.5.16

release: v0.5.15

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

release: v0.5.14

release: v0.5.13

release: v0.5.12

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>