## What's Changed
* feat(hooks): reduce log verbosity and improve error reporting in UI by @abhipatel12 in https://github.com/google-gemini/gemini-cli/pull/15297
* feat: simplify tool confirmation labels for better UX by @NTaylorMullen in https://github.com/google-gemini/gemini-cli/pull/15296
* chore/release: bump version to 0.21.0-nightly.20251219.70696e364 by @gemini-cli-robot in https://github.com/google-gemini/gemini-cli/pull/15301
* feat(core): Implement JIT context memory loading and UI sync by @SandyTao520 in https://github.com/google-gemini/gemini-cli/pull/14469
* feat(ui): Put "Allow for all future sessions" behind a setting off by default. by @jacob314 in https://github.com/google-gemini/gemini-cli/pull/15322
* fix(cli):change the placeholder of input during the shell mode by @JayadityaGit in https://github.com/google-gemini/gemini-cli/pull/15135
* Validate OAuth resource parameter matches MCP server URL by @galz10 in https://github.com/google-gemini/gemini-cli/pull/15289
* docs(cli): add System Prompt Override (GEMINI_SYSTEM_MD) by @ashmod in https://github.com/google-gemini/gemini-cli/pull/9515
* more robust command parsing logs by @scidomino in https://github.com/google-gemini/gemini-cli/pull/15339
* Introspection agent demo by @scidomino in https://github.com/google-gemini/gemini-cli/pull/15232
* fix(core): sanitize hook command expansion and prevent injection by @SandyTao520 in https://github.com/google-gemini/gemini-cli/pull/15343
**Full Changelog**: https://github.com/google-gemini/gemini-cli/compare/v0.21.0-nightly.20251219.70696e364...v0.21.0-nightly.20251220.41a1a3eed