feat(provider): add Gemini CLI provider

This commit introduces a new "Gemini CLI" provider, enabling users to leverage the authentication and free-tier access from the official Google Gemini CLI.

The provider works by reading the local OAuth credentials generated by the `gemini auth` command. It handles token refreshes, project discovery, and communicates with the same backend API as the CLI tool. This allows users to use Gemini models within the extension without needing a separate API key.

Key changes include:
- A new `GeminiCliHandler` in the backend for authentication and API communication.
- Model definitions for the available Gemini CLI models.
- A new settings UI for the Gemini CLI provider.
- Full test coverage for both the backend handler and the frontend UI.

Author: fxcl

.prototools

@@ -0,0 +1 @@
+pnpm = "10.8.1"

.vscode/settings.json

@@ -10,5 +10,14 @@
 	},
 	// Turn off tsc task auto detection since we have the necessary tasks as npm scripts
 	"typescript.tsc.autoDetect": "off",
-	"vitest.disableWorkspaceWarning": true
+	"vitest.disableWorkspaceWarning": true,
+	"workbench.colorCustomizations": {
+		"sash.hoverBorder": "#f8b367",
+		"statusBar.background": "#f69b36",
+		"statusBar.foreground": "#15202b",
+		"statusBarItem.hoverBackground": "#ee820b",
+		"statusBarItem.remoteBackground": "#f69b36",
+		"statusBarItem.remoteForeground": "#15202b"
+	},
+	"peacock.color": "#f69b36"
 }

packages/types/src/providers/gemini-cli.ts

@@ -0,0 +1,110 @@
+import type { ModelInfo } from "../model.js"
+
+// Gemini CLI models with free tier pricing (all $0)
+export type GeminiCliModelId = keyof typeof geminiCliModels
+
+export const geminiCliDefaultModelId: GeminiCliModelId = "gemini-2.0-flash-001"
+
+export const geminiCliModels = {
+	"gemini-2.0-flash-001": {
+		maxTokens: 8192,
+		contextWindow: 1_048_576,
+		supportsImages: true,
+		supportsPromptCache: false,
+		inputPrice: 0,
+		outputPrice: 0,
+	},
+	"gemini-2.0-flash-thinking-exp-01-21": {
+		maxTokens: 65_536,
+		contextWindow: 1_048_576,
+		supportsImages: true,
+		supportsPromptCache: false,
+		inputPrice: 0,
+		outputPrice: 0,
+	},
+	"gemini-2.0-flash-thinking-exp-1219": {
+		maxTokens: 8192,
+		contextWindow: 32_767,
+		supportsImages: true,
+		supportsPromptCache: false,
+		inputPrice: 0,
+		outputPrice: 0,
+	},
+	"gemini-2.0-flash-exp": {
+		maxTokens: 8192,
+		contextWindow: 1_048_576,
+		supportsImages: true,
+		supportsPromptCache: false,
+		inputPrice: 0,
+		outputPrice: 0,
+	},
+	"gemini-1.5-flash-002": {
+		maxTokens: 8192,
+		contextWindow: 1_048_576,
+		supportsImages: true,
+		supportsPromptCache: false,
+		inputPrice: 0,
+		outputPrice: 0,
+	},
+	"gemini-1.5-flash-exp-0827": {
+		maxTokens: 8192,
+		contextWindow: 1_048_576,
+		supportsImages: true,
+		supportsPromptCache: false,
+		inputPrice: 0,
+		outputPrice: 0,
+	},
+	"gemini-1.5-flash-8b-exp-0827": {
+		maxTokens: 8192,
+		contextWindow: 1_048_576,
+		supportsImages: true,
+		supportsPromptCache: false,
+		inputPrice: 0,
+		outputPrice: 0,
+	},
+	"gemini-1.5-pro-002": {
+		maxTokens: 8192,
+		contextWindow: 2_097_152,
+		supportsImages: true,
+		supportsPromptCache: false,
+		inputPrice: 0,
+		outputPrice: 0,
+	},
+	"gemini-1.5-pro-exp-0827": {
+		maxTokens: 8192,
+		contextWindow: 2_097_152,
+		supportsImages: true,
+		supportsPromptCache: false,
+		inputPrice: 0,
+		outputPrice: 0,
+	},
+	"gemini-exp-1206": {
+		maxTokens: 8192,
+		contextWindow: 2_097_152,
+		supportsImages: true,
+		supportsPromptCache: false,
+		inputPrice: 0,
+		outputPrice: 0,
+	},
+	"gemini-2.5-flash": {
+		maxTokens: 64_000,
+		contextWindow: 1_048_576,
+		supportsImages: true,
+		supportsPromptCache: false,
+		inputPrice: 0,
+		outputPrice: 0,
+		maxThinkingTokens: 24_576,
+		supportsReasoningBudget: true,
+	},
+	"gemini-2.5-pro": {
+		maxTokens: 64_000,
+		contextWindow: 1_048_576,
+		supportsImages: true,
+		supportsPromptCache: false,
+		inputPrice: 0,
+		outputPrice: 0,
+		maxThinkingTokens: 32_768,
+		supportsReasoningBudget: true,
+		requiredReasoningBudget: true,
+	},
+} as const satisfies Record<string, ModelInfo>

packages/types/src/providers/index.ts

@@ -4,6 +4,7 @@ export * from "./chutes.js"
 export * from "./claude-code.js"
 export * from "./deepseek.js"
 export * from "./gemini.js"
+export * from "./gemini-cli.js"
 export * from "./glama.js"
 export * from "./groq.js"
 export * from "./lite-llm.js"

src/api/index.ts

@@ -15,6 +15,7 @@ import {
 	OllamaHandler,
 	LmStudioHandler,
 	GeminiHandler,
+	GeminiCliHandler,
 	OpenAiNativeHandler,
 	DeepSeekHandler,
 	MistralHandler,
@@ -85,6 +86,8 @@ export function buildApiHandler(configuration: ProviderSettings): ApiHandler {
 			return new LmStudioHandler(options)
 		case "gemini":
 			return new GeminiHandler(options)
+		case "gemini-cli":
+			return new GeminiCliHandler(options)
 		case "openai-native":
 			return new OpenAiNativeHandler(options)
 		case "deepseek":