feat(ui): implement refreshed UX for Composer layout

- Promotes refreshed multi-row status area and footer as the default experience.
- Stabilizes Composer row heights to prevent layout 'jitter' during typing and model turns.
- Unifies active hook status and model loading indicators into a single, stable Row 1.
- Refactors settings to use backward-compatible 'Hide' booleans (ui.hideStatusTips, ui.hideStatusWit).
- Removes vestigial context usage bleed-through logic in minimal mode to align with global UX direction.
- Relocates toast notifications to the top status row for improved visibility.
- Updates all CLI UI snapshots and architectural tests to reflect the stabilized layout.

docs/tools/shell.md

@@ -120,14 +120,6 @@ tools to detect if they are being run from within the Gemini CLI.
 
 ## Command restrictions
 
-<!-- prettier-ignore -->
-> [!WARNING]
-> The `tools.core` setting is an **allowlist for _all_ built-in
-> tools**, not just shell commands. When you set `tools.core` to any value,
-> _only_ the tools explicitly listed will be enabled. This includes all built-in
-> tools like `read_file`, `write_file`, `glob`, `grep_search`, `list_directory`,
-> `replace`, etc.
-
 You can restrict the commands that can be executed by the `run_shell_command`
 tool by using the `tools.core` and `tools.exclude` settings in your
 configuration file.