Add Factory Droid as a converter target (#174)

Adds a new 'droid' target to the converter that outputs Claude Code plugins
in Factory Droid's format:

- Commands flattened to ~/.factory/commands/ (strips namespace prefixes)
- Agents converted to droids in ~/.factory/droids/ with proper frontmatter
- Skills copied to ~/.factory/skills/
- Content transforms: Task calls, slash commands, and @agent references
  adapted to Droid conventions

This resolves the manual workaround described in issue #31 by automating
the conversion from Claude Code plugin format to Factory Droid's expected
directory structure.

Includes 13 tests covering converter logic and file writer behavior.

Co-authored-by: adamprime <adamprime@hey.com>
Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>

src/targets/index.ts

@@ -1,10 +1,13 @@
 import type { ClaudePlugin } from "../types/claude"
 import type { OpenCodeBundle } from "../types/opencode"
 import type { CodexBundle } from "../types/codex"
+import type { DroidBundle } from "../types/droid"
 import { convertClaudeToOpenCode, type ClaudeToOpenCodeOptions } from "../converters/claude-to-opencode"
 import { convertClaudeToCodex } from "../converters/claude-to-codex"
+import { convertClaudeToDroid } from "../converters/claude-to-droid"
 import { writeOpenCodeBundle } from "./opencode"
 import { writeCodexBundle } from "./codex"
+import { writeDroidBundle } from "./droid"
 
 export type TargetHandler<TBundle = unknown> = {
   name: string
@@ -26,4 +29,10 @@ export const targets: Record<string, TargetHandler> = {
     convert: convertClaudeToCodex as TargetHandler<CodexBundle>["convert"],
     write: writeCodexBundle as TargetHandler<CodexBundle>["write"],
   },
+  droid: {
+    name: "droid",
+    implemented: true,
+    convert: convertClaudeToDroid as TargetHandler<DroidBundle>["convert"],
+    write: writeDroidBundle as TargetHandler<DroidBundle>["write"],
+  },
 }