feat(gemini): add Gemini CLI as sixth target provider

Add `--to gemini` support for both `convert` and `install` commands,
converting Claude Code plugins into Gemini CLI-compatible format.

- Agents convert to `.gemini/skills/*/SKILL.md` with description frontmatter
- Commands convert to `.gemini/commands/*.toml` with TOML prompt format
- Namespaced commands create directory structure (workflows:plan -> workflows/plan.toml)
- Skills pass through unchanged (identical SKILL.md standard)
- MCP servers written to `.gemini/settings.json` with merge support
- Content transforms: .claude/ paths, Task calls, @agent references
- Hooks emit warning (different format in Gemini)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/targets/index.ts

@@ -4,16 +4,19 @@ import type { CodexBundle } from "../types/codex"
 import type { DroidBundle } from "../types/droid"
 import type { CursorBundle } from "../types/cursor"
 import type { PiBundle } from "../types/pi"
+import type { GeminiBundle } from "../types/gemini"
 import { convertClaudeToOpenCode, type ClaudeToOpenCodeOptions } from "../converters/claude-to-opencode"
 import { convertClaudeToCodex } from "../converters/claude-to-codex"
 import { convertClaudeToDroid } from "../converters/claude-to-droid"
 import { convertClaudeToCursor } from "../converters/claude-to-cursor"
 import { convertClaudeToPi } from "../converters/claude-to-pi"
+import { convertClaudeToGemini } from "../converters/claude-to-gemini"
 import { writeOpenCodeBundle } from "./opencode"
 import { writeCodexBundle } from "./codex"
 import { writeDroidBundle } from "./droid"
 import { writeCursorBundle } from "./cursor"
 import { writePiBundle } from "./pi"
+import { writeGeminiBundle } from "./gemini"
 
 export type TargetHandler<TBundle = unknown> = {
   name: string
@@ -53,4 +56,10 @@ export const targets: Record<string, TargetHandler> = {
     convert: convertClaudeToPi as TargetHandler<PiBundle>["convert"],
     write: writePiBundle as TargetHandler<PiBundle>["write"],
   },
+  gemini: {
+    name: "gemini",
+    implemented: true,
+    convert: convertClaudeToGemini as TargetHandler<GeminiBundle>["convert"],
+    write: writeGeminiBundle as TargetHandler<GeminiBundle>["write"],
+  },
 }