refactor: removed voice control and git features from coding-agent

- Removed voice control and TTS features from coding-agent package.
- Removed git tool integration and worktree management from coding-agent.
- Deleted entire git-tool package and all git operations.
- Inlined OpenAI Codex prompt utilities and removed provider exports.

packages/coding-agent/test/python-tool-settings.test.ts

@@ -14,7 +14,6 @@ function createSettings(overrides?: Partial<ToolSession["settings"]>): ToolSessi
 		getLspDiagnosticsOnWrite: () => true,
 		getLspDiagnosticsOnEdit: () => false,
 		getEditFuzzyMatch: () => true,
-		getGitToolEnabled: () => false,
 		getBashInterceptorEnabled: () => false,
 		getBashInterceptorSimpleLsEnabled: () => true,
 		getBashInterceptorRules: () => [],