feat: add Gemini API key onboarding

docs/cli/index.md

@@ -165,8 +165,9 @@ Options:
 - `--workspace <dir>`
 - `--non-interactive`
 - `--mode <local|remote>`
-- `--auth-choice <oauth|claude-cli|openai-codex|codex-cli|antigravity|apiKey|minimax|skip>`
+- `--auth-choice <oauth|claude-cli|openai-codex|codex-cli|antigravity|gemini-api-key|apiKey|minimax|skip>`
 - `--anthropic-api-key <key>`
+- `--gemini-api-key <key>`
 - `--gateway-port <port>`
 - `--gateway-bind <loopback|lan|tailnet|auto>`
 - `--gateway-auth <off|token|password>`

docs/start/wizard.md

@@ -170,6 +170,17 @@ clawdbot onboard --non-interactive \
 
 Add `--json` for a machine‑readable summary.
 
+Gemini example:
+
+```bash
+clawdbot onboard --non-interactive \
+  --mode local \
+  --auth-choice gemini-api-key \
+  --gemini-api-key "$GEMINI_API_KEY" \
+  --gateway-port 18789 \
+  --gateway-bind loopback
+```
+
 Add agent (non‑interactive) example:
 
 ```bash