Docs: Add changelog for v.0.15.0 (#13276)

docs/changelogs/index.md

@@ -3,6 +3,52 @@
 Wondering what's new in Gemini CLI? This document provides key highlights and
 notable changes to Gemini CLI.
 
+## v0.15.0 - Gemini CLI weekly update - 2025-11-03
+
+- **🎉 Seamless scrollable UI & mouse support:** We’ve given Gemini CLI a major
+  facelift to make your terminal experience smoother and much more polished. You
+  now get a flicker-free display with sticky headers that keep important context
+  visible and a stable input prompt that doesn't jump around. We even added
+  mouse support so you can click right where you need to type!
+  ([gif](https://imgur.com/a/O6qc7bx),
+  [@jacob314](https://github.com/jacob314)).
+  - **Announcement:**
+    [https://developers.googleblog.com/en/making-the-terminal-beautiful-one-pixel-at-a-time/](https://developers.googleblog.com/en/making-the-terminal-beautiful-one-pixel-at-a-time/)
+- **🎉 New partner extensions:**
+  - **Arize:** Seamlessly instrument AI applications with Arize AX and grant
+    direct access to Arize support:
+
+    `gemini extensions install https://github.com/Arize-ai/arize-tracing-assistant`
+
+  - **Chronosphere:** Retrieve logs, metrics, traces, events, and specific
+    entities:
+
+    `gemini extensions install https://github.com/chronosphereio/chronosphere-mcp`
+
+  - **Transmit:** Comprehensive context, validation, and automated fixes for
+    creating production-ready authentication and identity workflows:
+
+    `gemini extensions install https://github.com/TransmitSecurity/transmit-security-journey-builder`
+
+- **Todo planning:** Complex questions now get broken down into todo lists that
+  the model can manage and check off. ([gif](https://imgur.com/a/EGDfNlZ),
+  [pr](https://github.com/google-gemini/gemini-cli/pull/12905) by
+  [@anj-s](https://github.com/anj-s))
+- **Disable GitHub extensions:** Users can now prevent the installation and
+  loading of extensions from GitHub.
+  ([pr](https://github.com/google-gemini/gemini-cli/pull/12838) by
+  [@kevinjwang1](https://github.com/kevinjwang1)).
+- **Extensions restart:** Users can now explicitly restart extensions using the
+  `/extensions restart` command.
+  ([pr](https://github.com/google-gemini/gemini-cli/pull/12739) by
+  [@jakemac53](https://github.com/jakemac53)).
+- **Better Angular support:** Angular workflows should now be more seamless
+  ([pr](https://github.com/google-gemini/gemini-cli/pull/10252) by
+  [@MarkTechson](https://github.com/MarkTechson)).
+- **Validate command:** Users can now check that local extensions are formatted
+  correctly. ([pr](https://github.com/google-gemini/gemini-cli/pull/12186) by
+  [@kevinjwang1](https://github.com/kevinjwang1)).
+
 ## v0.12.0 - Gemini CLI weekly update - 2025-10-27
 
 ![Codebase investigator subagent in Gemini CLI.](https://i.imgur.com/4J1njsx.png)

docs/cli/model-routing.md

@@ -0,0 +1,56 @@
+## Model Routing
+
+Gemini CLI includes a model routing feature that automatically switches to a
+fallback model in case of a model failure. This feature is enabled by default
+and provides resilience when the primary model is unavailable.
+
+## How it Works
+
+Model routing is not based on prompt complexity, but is a fallback mechanism.
+Here's how it works:
+
+1.  **Model Failure:** If the currently selected model fails to respond (for
+    example, due to a server error or other issue), the CLI will initiate the
+    fallback process.
+
+2.  **User Consent:** The CLI will prompt you to ask if you want to switch to
+    the fallback model. This is handled by the `fallbackModelHandler`.
+
+3.  **Fallback Activation:** If you consent, the CLI will activate the fallback
+    mode by calling `config.setFallbackMode(true)`.
+
+4.  **Model Switch:** On the next request, the CLI will use the
+    `DEFAULT_GEMINI_FLASH_MODEL` as the fallback model. This is handled by the
+    `resolveModel` function in
+    `packages/cli/src/zed-integration/zedIntegration.ts` which checks if
+    `isInFallbackMode()` is true.
+
+## Configuration
+
+Model routing is controlled by the `useModelRouter` setting in your
+`settings.json` file.
+
+- **`"experimental.useModelRouter": true` (Default):** Enables the model
+  routing/fallback feature.
+
+- **`"experimental.useModelRouter": false`:** Disables the model
+  routing/fallback feature. If a model fails, the CLI will not attempt to switch
+  to a fallback model.
+
+### Model Selection Precedence
+
+The model used by Gemini CLI is determined by the following order of precedence:
+
+1.  **`--model` command-line flag:** A model specified with the `--model` flag
+    when launching the CLI will always be used.
+2.  **`GEMINI_MODEL` environment variable:** If the `--model` flag is not used,
+    the CLI will use the model specified in the `GEMINI_MODEL` environment
+    variable.
+3.  **`model.name` in `settings.json`:** If neither of the above are set, the
+    model specified in the `model.name` property of your `settings.json` file
+    will be used.
+4.  **Default Model:** If none of the above are set, the default model will be
+    used. The default model is determined by the `useModelRouter` setting:
+    - If `useModelRouter` is `true`, the default model is `"auto"`.
+    - If `useModelRouter` is `false`, the default model is the standard Gemini
+      model.