Add remaining telemetry and updated modal text

[zanesq]

Summary

Add remaining telemetry and updated modal text

# Telemetry Events

## 1. `session_started` Event

Fired once when a new session begins.

### Properties

| Property | Type | Description |
|----------|------|-------------|
| `os` | string | Operating system (e.g., "macos", "linux", "windows") |
| `arch` | string | CPU architecture (e.g., "x86_64", "aarch64") |
| `version` | string | Goose version from Cargo.toml |
| `platform_version` | string | OS version (e.g., "15.1" on macOS, VERSION_ID on Linux) |
| `install_method` | string | How goose was installed: "homebrew", "cargo", "desktop", or "binary" |
| `interface` | string | How the session was started: "cli" or "desktop" |
| `is_resumed` | boolean | Whether this is a resumed session vs new session |
| `session_number` | number | Total number of sessions for this installation (increments each session) |
| `days_since_install` | number | Days since first session on this installation |
| `provider` | string | LLM provider name (e.g., "openai", "anthropic") |
| `model` | string | Model name (e.g., "gpt-4o", "claude-sonnet-4-20250514") |
| `extensions_count` | number | Number of enabled extensions |
| `extensions` | string[] | List of enabled extension names |
| `total_sessions` | number | Total sessions in session history |
| `total_tokens` | number | Total tokens used across all sessions |

## 2. `error` Event

Fired in real-time when a provider error occurs.

### Properties

| Property | Type | Description |
|----------|------|-------------|
| `error_type` | string | Error category (see values below) |
| `version` | string | Goose version |
| `interface` | string | "cli" or "desktop" |
| `os` | string | Operating system |
| `arch` | string | CPU architecture |
| `platform_version` | string | OS version |
| `provider` | string | LLM provider name |
| `model` | string | Model name |

### Error Types

| Value | Description |
|-------|-------------|
| `auth` | Authentication error |
| `context_length` | Context length exceeded |
| `rate_limit` | Rate limit exceeded |
| `server` | Server error |
| `request` | Request failed |
| `execution` | Execution error |
| `usage` | Usage data error |
| `not_implemented` | Unsupported operation |

## Unique Installation Identification

- **distinct_id**: Persistent `installation_id` (UUID v4) stored in `~/.local/state/goose/telemetry_installation.json`
- Unique per installation, persists across sessions
- Only regenerated if the file is deleted

[michaelneale]

tried it out and looks good. Error stuff I wanted to be sure wouldn't leak anyting but seems solid.